Somehow, setting a tint color makes gauge work :/.

[wxWidgets.git] / src / png / pngwutil.c

diff --git a/src/png/pngwutil.c b/src/png/pngwutil.c
index 19feb1d98c29af4eaa2da946276256eccec86d04..49e6a2d213b3b8a9991a3a6be1364b53b1f2a80c 100644 (file)
--- a/src/png/pngwutil.c
+++ b/src/png/pngwutil.c
@@ -1,8 +1,8 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
 
 /* pngwutil.c - utilities to write a PNG file
  *

- * Last changed in libpng 1.4.1 [February 25, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.2 [April 25, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson

  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *


@@ -11,11 +11,11 @@
  * and license in png.h
  */
 
  * and license in png.h
  */
 

-#define PNG_NO_PEDANTIC_WARNINGS
-#include "png.h"
-#ifdef PNG_WRITE_SUPPORTED

 #include "pngpriv.h"
 
 #include "pngpriv.h"
 

+#ifdef PNG_WRITE_SUPPORTED
+
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED

 /* Place a 32-bit number into a buffer in PNG byte order.  We work
  * with unsigned numbers for convenience, although one supported
  * ancillary chunk uses signed (two's complement) numbers.
 /* Place a 32-bit number into a buffer in PNG byte order.  We work
  * with unsigned numbers for convenience, although one supported
  * ancillary chunk uses signed (two's complement) numbers.


@@ -29,21 +29,6 @@ png_save_uint_32(png_bytep buf, png_uint_32 i)
    buf[3] = (png_byte)(i & 0xff);
 }
 
    buf[3] = (png_byte)(i & 0xff);
 }
 

-#ifdef PNG_SAVE_INT_32_SUPPORTED
-/* The png_save_int_32 function assumes integers are stored in two's
- * complement format.  If this isn't the case, then this routine needs to
- * be modified to write data in two's complement format.
- */
-void PNGAPI
-png_save_int_32(png_bytep buf, png_int_32 i)
-{
-   buf[0] = (png_byte)((i >> 24) & 0xff);
-   buf[1] = (png_byte)((i >> 16) & 0xff);
-   buf[2] = (png_byte)((i >> 8) & 0xff);
-   buf[3] = (png_byte)(i & 0xff);
-}
-#endif
-

 /* Place a 16-bit number into a buffer in PNG byte order.
  * The parameter is declared unsigned int, not png_uint_16,
  * just to avoid potential problems on pre-ANSI C compilers.
 /* Place a 16-bit number into a buffer in PNG byte order.
  * The parameter is declared unsigned int, not png_uint_16,
  * just to avoid potential problems on pre-ANSI C compilers.


@@ -54,6 +39,7 @@ png_save_uint_16(png_bytep buf, unsigned int i)
    buf[0] = (png_byte)((i >> 8) & 0xff);
    buf[1] = (png_byte)(i & 0xff);
 }
    buf[0] = (png_byte)((i >> 8) & 0xff);
    buf[1] = (png_byte)(i & 0xff);
 }

+#endif

 
 /* Simple function to write the signature.  If we have already written
  * the magic bytes of the signature, or more likely, the PNG stream is
 
 /* Simple function to write the signature.  If we have already written
  * the magic bytes of the signature, or more likely, the PNG stream is


@@ -62,7 +48,7 @@ png_save_uint_16(png_bytep buf, unsigned int i)
  * bytes have already been written.
  */
 void PNGAPI
  * bytes have already been written.
  */
 void PNGAPI

-png_write_sig(png_structp png_ptr)
+png_write_sig(png_structrp png_ptr)

 {
    png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
 
 {
    png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
 


@@ -74,42 +60,25 @@ png_write_sig(png_structp png_ptr)
    /* Write the rest of the 8 byte signature */
    png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
       (png_size_t)(8 - png_ptr->sig_bytes));
    /* Write the rest of the 8 byte signature */
    png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
       (png_size_t)(8 - png_ptr->sig_bytes));

+

    if (png_ptr->sig_bytes < 3)
       png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
 }
 
    if (png_ptr->sig_bytes < 3)
       png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
 }
 

-/* Write a PNG chunk all at once.  The type is an array of ASCII characters
- * representing the chunk name.  The array must be at least 4 bytes in
- * length, and does not need to be null terminated.  To be safe, pass the
- * pre-defined chunk names here, and if you need a new one, define it
- * where the others are defined.  The length is the length of the data.
- * All the data must be present.  If that is not possible, use the
- * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
- * functions instead.
- */
-void PNGAPI
-png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
-   png_bytep data, png_size_t length)
-{
-   if (png_ptr == NULL)
-      return;
-   png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
-   png_write_chunk_data(png_ptr, data, (png_size_t)length);
-   png_write_chunk_end(png_ptr);
-}
-

 /* Write the start of a PNG chunk.  The type is the chunk type.
  * The total_length is the sum of the lengths of all the data you will be
  * passing in png_write_chunk_data().
  */
 /* Write the start of a PNG chunk.  The type is the chunk type.
  * The total_length is the sum of the lengths of all the data you will be
  * passing in png_write_chunk_data().
  */

-void PNGAPI
-png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
-   png_uint_32 length)
+static void
+png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
+    png_uint_32 length)

 {
    png_byte buf[8];
 
 {
    png_byte buf[8];
 

-   png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
-      (unsigned long)length);
+#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
+   PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
+   png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
+#endif

 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;


@@ -123,13 +92,16 @@ png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
 
    /* Write the length and the chunk name */
    png_save_uint_32(buf, length);
 
    /* Write the length and the chunk name */
    png_save_uint_32(buf, length);

-   png_memcpy(buf + 4, chunk_name, 4);
-   png_write_data(png_ptr, buf, (png_size_t)8);
+   png_save_uint_32(buf + 4, chunk_name);
+   png_write_data(png_ptr, buf, 8);
+

    /* Put the chunk name into png_ptr->chunk_name */
    /* Put the chunk name into png_ptr->chunk_name */

-   png_memcpy(png_ptr->chunk_name, chunk_name, 4);
+   png_ptr->chunk_name = chunk_name;
+

    /* Reset the crc and run it over the chunk name */
    png_reset_crc(png_ptr);
    /* Reset the crc and run it over the chunk name */
    png_reset_crc(png_ptr);

-   png_calculate_crc(png_ptr, chunk_name, 4);
+
+   png_calculate_crc(png_ptr, buf + 4, 4);

 
 #ifdef PNG_IO_STATE_SUPPORTED
    /* Inform the I/O callback that chunk data will (possibly) be written.
 
 #ifdef PNG_IO_STATE_SUPPORTED
    /* Inform the I/O callback that chunk data will (possibly) be written.


@@ -139,20 +111,30 @@ png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
 #endif
 }
 
 #endif
 }
 

-/* Write the data of a PNG chunk started with png_write_chunk_start().
+void PNGAPI
+png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
+    png_uint_32 length)
+{
+   png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
+}
+
+/* Write the data of a PNG chunk started with png_write_chunk_header().

  * Note that multiple calls to this function are allowed, and that the
  * sum of the lengths from these calls *must* add up to the total_length
  * Note that multiple calls to this function are allowed, and that the
  * sum of the lengths from these calls *must* add up to the total_length

- * given to png_write_chunk_start().
+ * given to png_write_chunk_header().

  */
 void PNGAPI
  */
 void PNGAPI

-png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
+png_write_chunk_data(png_structrp png_ptr, png_const_bytep data,
+    png_size_t length)

 {
    /* Write the data, and run the CRC over it */
    if (png_ptr == NULL)
       return;
 {
    /* Write the data, and run the CRC over it */
    if (png_ptr == NULL)
       return;

+

    if (data != NULL && length > 0)
    {
       png_write_data(png_ptr, data, length);
    if (data != NULL && length > 0)
    {
       png_write_data(png_ptr, data, length);

+

       /* Update the CRC after writing the data,
        * in case that the user I/O routine alters it.
        */
       /* Update the CRC after writing the data,
        * in case that the user I/O routine alters it.
        */


@@ -160,9 +142,9 @@ png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
    }
 }
 
    }
 }
 

-/* Finish a chunk started with png_write_chunk_start(). */
+/* Finish a chunk started with png_write_chunk_header(). */

 void PNGAPI
 void PNGAPI

-png_write_chunk_end(png_structp png_ptr)
+png_write_chunk_end(png_structrp png_ptr)

 {
    png_byte buf[4];
 
 {
    png_byte buf[4];
 


@@ -181,231 +163,586 @@ png_write_chunk_end(png_structp png_ptr)
    png_write_data(png_ptr, buf, (png_size_t)4);
 }
 
    png_write_data(png_ptr, buf, (png_size_t)4);
 }
 

-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
-/* This pair of functions encapsulates the operation of (a) compressing a
- * text string, and (b) issuing it later as a series of chunk data writes.
- * The compression_state structure is shared context for these functions
- * set up by the caller in order to make the whole mess thread-safe.
+/* Write a PNG chunk all at once.  The type is an array of ASCII characters
+ * representing the chunk name.  The array must be at least 4 bytes in
+ * length, and does not need to be null terminated.  To be safe, pass the
+ * pre-defined chunk names here, and if you need a new one, define it
+ * where the others are defined.  The length is the length of the data.
+ * All the data must be present.  If that is not possible, use the
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
+ * functions instead.

  */
  */

-
-typedef struct
+static void
+png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
+   png_const_bytep data, png_size_t length)

 {
 {

-   char *input;   /* The uncompressed input data */
-   int input_len;   /* Its length */
-   int num_output_ptr; /* Number of output pointers used */
-   int max_output_ptr; /* Size of output_ptr */
-   png_charpp output_ptr; /* Array of pointers to output */
-} compression_state;
+   if (png_ptr == NULL)
+      return;
+
+   /* On 64 bit architectures 'length' may not fit in a png_uint_32. */
+   if (length > PNG_UINT_31_MAX)
+      png_error(png_ptr, "length exceeds PNG maxima");
+
+   png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
+   png_write_chunk_data(png_ptr, data, length);
+   png_write_chunk_end(png_ptr);
+}

 
 

-/* Compress given text into storage in the png_ptr structure */
-static int /* PRIVATE */
-png_text_compress(png_structp png_ptr,
-        png_charp text, png_size_t text_len, int compression,
-        compression_state *comp)
+/* This is the API that calls the internal function above. */
+void PNGAPI
+png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
+   png_const_bytep data, png_size_t length)

 {
 {

-   int ret;
+   png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
+      length);
+}

 
 

-   comp->num_output_ptr = 0;
-   comp->max_output_ptr = 0;
-   comp->output_ptr = NULL;
-   comp->input = NULL;
-   comp->input_len = 0;
+/* This is used below to find the size of an image to pass to png_deflate_claim,
+ * so it only needs to be accurate if the size is less than 16384 bytes (the
+ * point at which a lower LZ window size can be used.)
+ */
+static png_alloc_size_t
+png_image_size(png_structrp png_ptr)
+{
+   /* Only return sizes up to the maximum of a png_uint_32, do this by limiting
+    * the width and height used to 15 bits.
+    */
+   png_uint_32 h = png_ptr->height;

 
 

-   /* We may just want to pass the text right through */
-   if (compression == PNG_TEXT_COMPRESSION_NONE)
+   if (png_ptr->rowbytes < 32768 && h < 32768)

    {
    {

-       comp->input = text;
-       comp->input_len = text_len;
-       return((int)text_len);
+      if (png_ptr->interlaced)
+      {
+         /* Interlacing makes the image larger because of the replication of
+          * both the filter byte and the padding to a byte boundary.
+          */
+         png_uint_32 w = png_ptr->width;
+         unsigned int pd = png_ptr->pixel_depth;
+         png_alloc_size_t cb_base;
+         int pass;
+
+         for (cb_base=0, pass=0; pass<=6; ++pass)
+         {
+            png_uint_32 pw = PNG_PASS_COLS(w, pass);
+
+            if (pw > 0)
+               cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
+         }
+
+         return cb_base;
+      }
+
+      else
+         return (png_ptr->rowbytes+1) * h;

    }
 
    }
 

-   if (compression >= PNG_TEXT_COMPRESSION_LAST)
+   else
+      return 0xffffffffU;
+}
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+   /* This is the code to hack the first two bytes of the deflate stream (the
+    * deflate header) to correct the windowBits value to match the actual data
+    * size.  Note that the second argument is the *uncompressed* size but the
+    * first argument is the *compressed* data (and it must be deflate
+    * compressed.)
+    */
+static void
+optimize_cmf(png_bytep data, png_alloc_size_t data_size)
+{
+   /* Optimize the CMF field in the zlib stream.  The resultant zlib stream is
+    * still compliant to the stream specification.
+    */
+   if (data_size <= 16384) /* else windowBits must be 15 */

    {
    {

-#ifdef PNG_STDIO_SUPPORTED
-      char msg[50];
-      png_snprintf(msg, 50, "Unknown compression type %d", compression);
-      png_warning(png_ptr, msg);
-#else
-      png_warning(png_ptr, "Unknown compression type");
-#endif
+      unsigned int z_cmf = data[0];  /* zlib compression method and flags */
+
+      if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+      {
+         unsigned int z_cinfo;
+         unsigned int half_z_window_size;
+
+         z_cinfo = z_cmf >> 4;
+         half_z_window_size = 1U << (z_cinfo + 7);
+
+         if (data_size <= half_z_window_size) /* else no change */
+         {
+            unsigned int tmp;
+
+            do
+            {
+               half_z_window_size >>= 1;
+               --z_cinfo;
+            }
+            while (z_cinfo > 0 && data_size <= half_z_window_size);
+
+            z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+
+            data[0] = (png_byte)z_cmf;
+            tmp = data[1] & 0xe0;
+            tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+            data[1] = (png_byte)tmp;
+         }
+      }

    }
    }

+}
+#else
+#  define optimize_cmf(dp,dl) ((void)0)
+#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */

 
 

-   /* We can't write the chunk until we find out how much data we have,
-    * which means we need to run the compressor first and save the
-    * output.  This shouldn't be a problem, as the vast majority of
-    * comments should be reasonable, but we will set up an array of
-    * malloc'd pointers to be sure.
-    *
-    * If we knew the application was well behaved, we could simplify this
-    * greatly by assuming we can always malloc an output buffer large
-    * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
-    * and malloc this directly.  The only time this would be a bad idea is
-    * if we can't malloc more than 64K and we have 64K of random input
-    * data, or if the input string is incredibly large (although this
-    * wouldn't cause a failure, just a slowdown due to swapping).
-    */
+/* Initialize the compressor for the appropriate type of compression. */
+static int
+png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
+   png_alloc_size_t data_size)
+{
+   if (png_ptr->zowner != 0)
+   {
+      char msg[64];
+
+      PNG_STRING_FROM_CHUNK(msg, owner);
+      msg[4] = ':';
+      msg[5] = ' ';
+      PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner);
+      /* So the message that results is "<chunk> using zstream"; this is an
+       * internal error, but is very useful for debugging.  i18n requirements
+       * are minimal.
+       */
+      (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
+#     if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+         png_warning(png_ptr, msg);
+
+         /* Attempt sane error recovery */
+         if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
+         {
+            png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
+            return Z_STREAM_ERROR;
+         }

 
 

-   /* Set up the compression buffers */
-   png_ptr->zstream.avail_in = (uInt)text_len;
-   png_ptr->zstream.next_in = (Bytef *)text;
-   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-   png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
+         png_ptr->zowner = 0;
+#     else
+         png_error(png_ptr, msg);
+#     endif
+   }

 
 

-   /* This is the same compression loop as in png_write_row() */
-   do

    {
    {

-      /* Compress the data */
-      ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
-      if (ret != Z_OK)
+      int level = png_ptr->zlib_level;
+      int method = png_ptr->zlib_method;
+      int windowBits = png_ptr->zlib_window_bits;
+      int memLevel = png_ptr->zlib_mem_level;
+      int strategy; /* set below */
+      int ret; /* zlib return code */
+
+      if (owner == png_IDAT)

       {
       {

-         /* Error */
-         if (png_ptr->zstream.msg != NULL)
-            png_error(png_ptr, png_ptr->zstream.msg);
+         if (png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)
+            strategy = png_ptr->zlib_strategy;
+
+         else if (png_ptr->do_filter != PNG_FILTER_NONE)
+            strategy = PNG_Z_DEFAULT_STRATEGY;
+

          else
          else

-            png_error(png_ptr, "zlib error");
+            strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;

       }
       }

-      /* Check to see if we need more room */
-      if (!(png_ptr->zstream.avail_out))
+
+      else

       {
       {

-         /* Make sure the output array has room */
-         if (comp->num_output_ptr >= comp->max_output_ptr)
-         {
-            int old_max;
+#        ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+            level = png_ptr->zlib_text_level;
+            method = png_ptr->zlib_text_method;
+            windowBits = png_ptr->zlib_text_window_bits;
+            memLevel = png_ptr->zlib_text_mem_level;
+            strategy = png_ptr->zlib_text_strategy;
+#        else
+            /* If customization is not supported the values all come from the
+             * IDAT values except for the strategy, which is fixed to the
+             * default.  (This is the pre-1.6.0 behavior too, although it was
+             * implemented in a very different way.)
+             */
+            strategy = Z_DEFAULT_STRATEGY;
+#        endif
+      }
+
+      /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
+       * happening just pass 32768 as the data_size parameter.  Notice that zlib
+       * requires an extra 262 bytes in the window in addition to the data to be
+       * able to see the whole of the data, so if data_size+262 takes us to the
+       * next windowBits size we need to fix up the value later.  (Because even
+       * though deflate needs the extra window, inflate does not!)
+       */
+      if (data_size <= 16384)
+      {
+         /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
+          * work round a Microsoft Visual C misbehavior which, contrary to C-90,
+          * widens the result of the following shift to 64-bits if (and,
+          * apparently, only if) it is used in a test.
+          */
+         unsigned int half_window_size = 1U << (windowBits-1);

 
 

-            old_max = comp->max_output_ptr;
-            comp->max_output_ptr = comp->num_output_ptr + 4;
-            if (comp->output_ptr != NULL)
-            {
-               png_charpp old_ptr;
-
-               old_ptr = comp->output_ptr;
-               comp->output_ptr = (png_charpp)png_malloc(png_ptr,
-                  (png_alloc_size_t)
-                  (comp->max_output_ptr * png_sizeof(png_charpp)));
-               png_memcpy(comp->output_ptr, old_ptr, old_max
-                  * png_sizeof(png_charp));
-               png_free(png_ptr, old_ptr);
-            }
-            else
-               comp->output_ptr = (png_charpp)png_malloc(png_ptr,
-                  (png_alloc_size_t)
-                  (comp->max_output_ptr * png_sizeof(png_charp)));
+         while (data_size + 262 <= half_window_size)
+         {
+            half_window_size >>= 1;
+            --windowBits;

          }
          }

+      }

 
 

-         /* Save the data */
-         comp->output_ptr[comp->num_output_ptr] =
-            (png_charp)png_malloc(png_ptr,
-            (png_alloc_size_t)png_ptr->zbuf_size);
-         png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
-            png_ptr->zbuf_size);
-         comp->num_output_ptr++;
+      /* Check against the previous initialized values, if any. */
+      if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) &&
+         (png_ptr->zlib_set_level != level ||
+         png_ptr->zlib_set_method != method ||
+         png_ptr->zlib_set_window_bits != windowBits ||
+         png_ptr->zlib_set_mem_level != memLevel ||
+         png_ptr->zlib_set_strategy != strategy))
+      {
+         if (deflateEnd(&png_ptr->zstream) != Z_OK)
+            png_warning(png_ptr, "deflateEnd failed (ignored)");

 
 

-         /* and reset the buffer */
-         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-         png_ptr->zstream.next_out = png_ptr->zbuf;
+         png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;

       }
       }

-   /* Continue until we don't have any more to compress */
-   } while (png_ptr->zstream.avail_in);

 
 

-   /* Finish the compression */
-   do
-   {
-      /* Tell zlib we are finished */
-      ret = deflate(&png_ptr->zstream, Z_FINISH);
+      /* For safety clear out the input and output pointers (currently zlib
+       * doesn't use them on Init, but it might in the future).
+       */
+      png_ptr->zstream.next_in = NULL;
+      png_ptr->zstream.avail_in = 0;
+      png_ptr->zstream.next_out = NULL;
+      png_ptr->zstream.avail_out = 0;
+
+      /* Now initialize if required, setting the new parameters, otherwise just
+       * to a simple reset to the previous parameters.
+       */
+      if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
+         ret = deflateReset(&png_ptr->zstream);
+
+      else
+      {
+         ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
+            memLevel, strategy);
+
+         if (ret == Z_OK)
+            png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+      }

 
 

+      /* The return code is from either deflateReset or deflateInit2; they have
+       * pretty much the same set of error codes.
+       */

       if (ret == Z_OK)
       if (ret == Z_OK)

+         png_ptr->zowner = owner;
+
+      else
+         png_zstream_error(png_ptr, ret);
+
+      return ret;
+   }
+}
+
+/* Clean up (or trim) a linked list of compression buffers. */
+void /* PRIVATE */
+png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
+{
+   png_compression_bufferp list = *listp;
+
+   if (list != NULL)
+   {
+      *listp = NULL;
+
+      do

       {
       {

-         /* Check to see if we need more room */
-         if (!(png_ptr->zstream.avail_out))
+         png_compression_bufferp next = list->next;
+
+         png_free(png_ptr, list);
+         list = next;
+      }
+      while (list != NULL);
+   }
+}
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller to allow access to the relevant local variables.
+ *
+ * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
+ * temporary buffers.  From 1.6.0 it is retained in png_struct so that it will
+ * be correctly freed in the event of a write error (previous implementations
+ * just leaked memory.)
+ */
+typedef struct
+{
+   png_const_bytep      input;        /* The uncompressed input data */
+   png_alloc_size_t     input_len;    /* Its length */
+   png_uint_32          output_len;   /* Final compressed length */
+   png_byte             output[1024]; /* First block of output */
+} compression_state;
+
+static void
+png_text_compress_init(compression_state *comp, png_const_bytep input,
+   png_alloc_size_t input_len)
+{
+   comp->input = input;
+   comp->input_len = input_len;
+   comp->output_len = 0;
+}
+
+/* Compress the data in the compression state input */
+static int
+png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
+   compression_state *comp, png_uint_32 prefix_len)
+{
+   int ret;
+
+   /* To find the length of the output it is necessary to first compress the
+    * input, the result is buffered rather than using the two-pass algorithm
+    * that is used on the inflate side; deflate is assumed to be slower and a
+    * PNG writer is assumed to have more memory available than a PNG reader.
+    *
+    * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
+    * upper limit on the output size, but it is always bigger than the input
+    * size so it is likely to be more efficient to use this linked-list
+    * approach.
+    */
+   ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
+
+   if (ret != Z_OK)
+      return ret;
+
+   /* Set up the compression buffers, we need a loop here to avoid overflowing a
+    * uInt.  Use ZLIB_IO_MAX to limit the input.  The output is always limited
+    * by the output buffer size, so there is no need to check that.  Since this
+    * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
+    * in size.
+    */
+   {
+      png_compression_bufferp *end = &png_ptr->zbuffer_list;
+      png_alloc_size_t input_len = comp->input_len; /* may be zero! */
+      png_uint_32 output_len;
+
+      /* zlib updates these for us: */
+      png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
+      png_ptr->zstream.avail_in = 0; /* Set below */
+      png_ptr->zstream.next_out = comp->output;
+      png_ptr->zstream.avail_out = (sizeof comp->output);
+
+      output_len = png_ptr->zstream.avail_out;
+
+      do
+      {
+         uInt avail_in = ZLIB_IO_MAX;
+
+         if (avail_in > input_len)
+            avail_in = (uInt)input_len;
+
+         input_len -= avail_in;
+
+         png_ptr->zstream.avail_in = avail_in;
+
+         if (png_ptr->zstream.avail_out == 0)

          {
          {

-            /* Check to make sure our output array has room */
-            if (comp->num_output_ptr >= comp->max_output_ptr)
+            png_compression_buffer *next;
+
+            /* Chunk data is limited to 2^31 bytes in length, so the prefix
+             * length must be counted here.
+             */
+            if (output_len + prefix_len > PNG_UINT_31_MAX)

             {
             {

-               int old_max;
+               ret = Z_MEM_ERROR;
+               break;
+            }

 
 

-               old_max = comp->max_output_ptr;
-               comp->max_output_ptr = comp->num_output_ptr + 4;
-               if (comp->output_ptr != NULL)
+            /* Need a new (malloc'ed) buffer, but there may be one present
+             * already.
+             */
+            next = *end;
+            if (next == NULL)
+            {
+               next = png_voidcast(png_compression_bufferp, png_malloc_base
+                  (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+
+               if (next == NULL)

                {
                {

-                  png_charpp old_ptr;
-
-                  old_ptr = comp->output_ptr;
-                  /* This could be optimized to realloc() */
-                  comp->output_ptr = (png_charpp)png_malloc(png_ptr,
-                     (png_alloc_size_t)(comp->max_output_ptr *
-                     png_sizeof(png_charp)));
-                  png_memcpy(comp->output_ptr, old_ptr,
-                     old_max * png_sizeof(png_charp));
-                  png_free(png_ptr, old_ptr);
+                  ret = Z_MEM_ERROR;
+                  break;

                }
                }

-               else
-                  comp->output_ptr = (png_charpp)png_malloc(png_ptr,
-                     (png_alloc_size_t)(comp->max_output_ptr *
-                     png_sizeof(png_charp)));
+
+               /* Link in this buffer (so that it will be freed later) */
+               next->next = NULL;
+               *end = next;

             }
 
             }
 

-            /* Save the data */
-            comp->output_ptr[comp->num_output_ptr] =
-               (png_charp)png_malloc(png_ptr,
-               (png_alloc_size_t)png_ptr->zbuf_size);
-            png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
-               png_ptr->zbuf_size);
-            comp->num_output_ptr++;
-
-            /* and reset the buffer pointers */
-            png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-            png_ptr->zstream.next_out = png_ptr->zbuf;
+            png_ptr->zstream.next_out = next->output;
+            png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+            output_len += png_ptr->zstream.avail_out;
+
+            /* Move 'end' to the next buffer pointer. */
+            end = &next->next;

          }
          }

+
+         /* Compress the data */
+         ret = deflate(&png_ptr->zstream,
+            input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
+
+         /* Claw back input data that was not consumed (because avail_in is
+          * reset above every time round the loop).
+          */
+         input_len += png_ptr->zstream.avail_in;
+         png_ptr->zstream.avail_in = 0; /* safety */

       }
       }

-      else if (ret != Z_STREAM_END)
+      while (ret == Z_OK);
+
+      /* There may be some space left in the last output buffer, this needs to
+       * be subtracted from output_len.
+       */
+      output_len -= png_ptr->zstream.avail_out;
+      png_ptr->zstream.avail_out = 0; /* safety */
+      comp->output_len = output_len;
+
+      /* Now double check the output length, put in a custom message if it is
+       * too long.  Otherwise ensure the z_stream::msg pointer is set to
+       * something.
+       */
+      if (output_len + prefix_len >= PNG_UINT_31_MAX)

       {
       {

-         /* We got an error */
-         if (png_ptr->zstream.msg != NULL)
-            png_error(png_ptr, png_ptr->zstream.msg);
-         else
-            png_error(png_ptr, "zlib error");
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
+         ret = Z_MEM_ERROR;

       }
       }

-   } while (ret != Z_STREAM_END);

 
 

-   /* Text length is number of buffers plus last buffer */
-   text_len = png_ptr->zbuf_size * comp->num_output_ptr;
-   if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
-      text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
+      else
+         png_zstream_error(png_ptr, ret);
+
+      /* Reset zlib for another zTXt/iTXt or image data */
+      png_ptr->zowner = 0;

 
 

-   return((int)text_len);
+      /* The only success case is Z_STREAM_END, input_len must be 0, if not this
+       * is an internal error.
+       */
+      if (ret == Z_STREAM_END && input_len == 0)
+      {
+         /* Fix up the deflate header, if required */
+         optimize_cmf(comp->output, comp->input_len);
+
+         /* But Z_OK is returned, not Z_STREAM_END; this allows the claim
+          * function above to return Z_STREAM_END on an error (though it never
+          * does in the current versions of zlib.)
+          */
+         return Z_OK;
+      }
+
+      else
+         return ret;
+   }

 }
 
 /* Ship the compressed text out via chunk writes */
 }
 
 /* Ship the compressed text out via chunk writes */

-static void /* PRIVATE */
-png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
+static void
+png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)

 {
 {

-   int i;
+   png_uint_32 output_len = comp->output_len;
+   png_const_bytep output = comp->output;
+   png_uint_32 avail = (sizeof comp->output);
+   png_compression_buffer *next = png_ptr->zbuffer_list;

 
 

-   /* Handle the no-compression case */
-   if (comp->input)
+   for (;;)

    {
    {

-      png_write_chunk_data(png_ptr, (png_bytep)comp->input,
-                            (png_size_t)comp->input_len);
-      return;
+      if (avail > output_len)
+         avail = output_len;
+
+      png_write_chunk_data(png_ptr, output, avail);
+
+      output_len -= avail;
+
+      if (output_len == 0 || next == NULL)
+         break;
+
+      avail = png_ptr->zbuffer_size;
+      output = next->output;
+      next = next->next;
+   }
+
+   /* This is an internal error; 'next' must have been NULL! */
+   if (output_len > 0)
+      png_error(png_ptr, "error writing ancillary chunked compressed data");
+}
+#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
+
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
+    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
+ * and if invalid, correct the keyword rather than discarding the entire
+ * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
+ * length, forbids leading or trailing whitespace, multiple internal spaces,
+ * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
+ *
+ * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
+ * trailing '\0').  If this routine returns 0 then there was no keyword, or a
+ * valid one could not be generated, and the caller must png_error.
+ */
+static png_uint_32
+png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
+{
+   png_const_charp orig_key = key;
+   png_uint_32 key_len = 0;
+   int bad_character = 0;
+   int space = 1;
+
+   png_debug(1, "in png_check_keyword");
+
+   if (key == NULL)
+   {
+      *new_key = 0;
+      return 0;
+   }
+
+   while (*key && key_len < 79)
+   {
+      png_byte ch = (png_byte)(0xff & *key++);
+
+      if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
+         *new_key++ = ch, ++key_len, space = 0;
+
+      else if (!space)
+      {
+         /* A space or an invalid character when one wasn't seen immediately
+          * before; output just a space.
+          */
+         *new_key++ = 32, ++key_len, space = 1;
+
+         /* If the character was not a space then it is invalid. */
+         if (ch != 32)
+            bad_character = ch;
+      }
+
+      else if (!bad_character)
+         bad_character = ch; /* just skip it, record the first error */
+   }
+
+   if (key_len > 0 && space) /* trailing space */
+   {
+      --key_len, --new_key;
+      if (!bad_character)
+         bad_character = 32;

    }
 
    }
 

-   /* Write saved output buffers, if any */
-   for (i = 0; i < comp->num_output_ptr; i++)
+   /* Terminate the keyword */
+   *new_key = 0;
+
+   if (key_len == 0)
+      return 0;
+
+   /* Try to only output one warning per keyword: */
+   if (*key) /* keyword too long */
+      png_warning(png_ptr, "keyword truncated");
+
+   else if (bad_character)

    {
    {

-      png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
-         (png_size_t)png_ptr->zbuf_size);
-      png_free(png_ptr, comp->output_ptr[i]);
+      PNG_WARNING_PARAMETERS(p)
+
+      png_warning_parameter(p, 1, orig_key);
+      png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
+
+      png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");

    }
    }

-   if (comp->max_output_ptr != 0)
-      png_free(png_ptr, comp->output_ptr);
-   /* Write anything left in zbuf */
-   if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
-      png_write_chunk_data(png_ptr, png_ptr->zbuf,
-         (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));

 
 

-   /* Reset zlib for another zTXt/iTXt or image data */
-   deflateReset(&png_ptr->zstream);
-   png_ptr->zstream.data_type = Z_BINARY;
+   return key_len;

 }
 #endif
 
 }
 #endif
 


@@ -414,13 +751,10 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
  * information being correct.
  */
 void /* PRIVATE */
  * information being correct.
  */
 void /* PRIVATE */

-png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
-   int bit_depth, int color_type, int compression_type, int filter_type,
-   int interlace_type)
+png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
+    int bit_depth, int color_type, int compression_type, int filter_type,
+    int interlace_type)

 {
 {

-   PNG_IHDR;
-   int ret;
-

    png_byte buf[13]; /* Buffer to store the IHDR info */
 
    png_debug(1, "in png_write_IHDR");
    png_byte buf[13]; /* Buffer to store the IHDR info */
 
    png_debug(1, "in png_write_IHDR");


@@ -435,36 +769,61 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
             case 2:
             case 4:
             case 8:
             case 2:
             case 4:
             case 8:

-            case 16: png_ptr->channels = 1; break;
-            default: png_error(png_ptr,
-                         "Invalid bit depth for grayscale image");
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+            case 16:
+#endif
+               png_ptr->channels = 1; break;
+
+            default:
+               png_error(png_ptr,
+                   "Invalid bit depth for grayscale image");

          }
          break;
          }
          break;

+

       case PNG_COLOR_TYPE_RGB:
       case PNG_COLOR_TYPE_RGB:

+#ifdef PNG_WRITE_16BIT_SUPPORTED

          if (bit_depth != 8 && bit_depth != 16)
          if (bit_depth != 8 && bit_depth != 16)

+#else
+         if (bit_depth != 8)
+#endif

             png_error(png_ptr, "Invalid bit depth for RGB image");
             png_error(png_ptr, "Invalid bit depth for RGB image");

+

          png_ptr->channels = 3;
          break;
          png_ptr->channels = 3;
          break;

+

       case PNG_COLOR_TYPE_PALETTE:
          switch (bit_depth)
          {
             case 1:
             case 2:
             case 4:
       case PNG_COLOR_TYPE_PALETTE:
          switch (bit_depth)
          {
             case 1:
             case 2:
             case 4:

-            case 8: png_ptr->channels = 1; break;
-            default: png_error(png_ptr, "Invalid bit depth for paletted image");
+            case 8:
+               png_ptr->channels = 1;
+               break;
+
+            default:
+               png_error(png_ptr, "Invalid bit depth for paletted image");

          }
          break;
          }
          break;

+

       case PNG_COLOR_TYPE_GRAY_ALPHA:
          if (bit_depth != 8 && bit_depth != 16)
             png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
       case PNG_COLOR_TYPE_GRAY_ALPHA:
          if (bit_depth != 8 && bit_depth != 16)
             png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");

+

          png_ptr->channels = 2;
          break;
          png_ptr->channels = 2;
          break;

+

       case PNG_COLOR_TYPE_RGB_ALPHA:
       case PNG_COLOR_TYPE_RGB_ALPHA:

+#ifdef PNG_WRITE_16BIT_SUPPORTED

          if (bit_depth != 8 && bit_depth != 16)
          if (bit_depth != 8 && bit_depth != 16)

+#else
+         if (bit_depth != 8)
+#endif

             png_error(png_ptr, "Invalid bit depth for RGBA image");
             png_error(png_ptr, "Invalid bit depth for RGBA image");

+

          png_ptr->channels = 4;
          break;
          png_ptr->channels = 4;
          break;

+

       default:
          png_error(png_ptr, "Invalid image color type specified");
    }
       default:
          png_error(png_ptr, "Invalid image color type specified");
    }


@@ -486,13 +845,13 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
     */
    if (
 #ifdef PNG_MNG_FEATURES_SUPPORTED
     */
    if (
 #ifdef PNG_MNG_FEATURES_SUPPORTED

-      !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
-      ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
-      (color_type == PNG_COLOR_TYPE_RGB ||
-       color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
-      (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
+       !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+       ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
+       (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
+       (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&

 #endif
 #endif

-      filter_type != PNG_FILTER_TYPE_BASE)
+       filter_type != PNG_FILTER_TYPE_BASE)

    {
       png_warning(png_ptr, "Invalid filter type specified");
       filter_type = PNG_FILTER_TYPE_BASE;
    {
       png_warning(png_ptr, "Invalid filter type specified");
       filter_type = PNG_FILTER_TYPE_BASE;


@@ -500,7 +859,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    if (interlace_type != PNG_INTERLACE_NONE &&
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    if (interlace_type != PNG_INTERLACE_NONE &&

-      interlace_type != PNG_INTERLACE_ADAM7)
+       interlace_type != PNG_INTERLACE_ADAM7)

    {
       png_warning(png_ptr, "Invalid interlace type specified");
       interlace_type = PNG_INTERLACE_ADAM7;
    {
       png_warning(png_ptr, "Invalid interlace type specified");
       interlace_type = PNG_INTERLACE_ADAM7;


@@ -537,55 +896,19 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
    buf[12] = (png_byte)interlace_type;
 
    /* Write the chunk */
    buf[12] = (png_byte)interlace_type;
 
    /* Write the chunk */

-   png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
+   png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);

 
 

-   /* Initialize zlib with PNG info */
-   png_ptr->zstream.zalloc = png_zalloc;
-   png_ptr->zstream.zfree = png_zfree;
-   png_ptr->zstream.opaque = (voidpf)png_ptr;

    if (!(png_ptr->do_filter))
    {
       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
    if (!(png_ptr->do_filter))
    {
       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||

-         png_ptr->bit_depth < 8)
+          png_ptr->bit_depth < 8)

          png_ptr->do_filter = PNG_FILTER_NONE;
          png_ptr->do_filter = PNG_FILTER_NONE;

+

       else
          png_ptr->do_filter = PNG_ALL_FILTERS;
    }
       else
          png_ptr->do_filter = PNG_ALL_FILTERS;
    }

-   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
-   {
-      if (png_ptr->do_filter != PNG_FILTER_NONE)
-         png_ptr->zlib_strategy = Z_FILTERED;
-      else
-         png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
-   }
-   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
-      png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
-   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
-      png_ptr->zlib_mem_level = 8;
-   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
-      png_ptr->zlib_window_bits = 15;
-   if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
-      png_ptr->zlib_method = 8;
-   ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
-         png_ptr->zlib_method, png_ptr->zlib_window_bits,
-         png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
-   if (ret != Z_OK)
-   {
-      if (ret == Z_VERSION_ERROR) png_error(png_ptr,
-          "zlib failed to initialize compressor -- version error");
-      if (ret == Z_STREAM_ERROR) png_error(png_ptr,
-           "zlib failed to initialize compressor -- stream error");
-      if (ret == Z_MEM_ERROR) png_error(png_ptr,
-           "zlib failed to initialize compressor -- mem error");
-      png_error(png_ptr, "zlib failed to initialize compressor");
-   }
-   png_ptr->zstream.next_out = png_ptr->zbuf;
-   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-   /* libpng is not interested in zstream.data_type */
-   /* Set it to a predefined value, to avoid its evaluation inside zlib */
-   png_ptr->zstream.data_type = Z_BINARY;
-
-   png_ptr->mode = PNG_HAVE_IHDR;
+
+   png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */

 }
 
 /* Write the palette.  We are careful not to trust png_color to be in the
 }
 
 /* Write the palette.  We are careful not to trust png_color to be in the


@@ -593,45 +916,47 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
  * structure.
  */
 void /* PRIVATE */
  * structure.
  */
 void /* PRIVATE */

-png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
+png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
+    png_uint_32 num_pal)

 {
 {

-   PNG_PLTE;

    png_uint_32 i;
    png_uint_32 i;

-   png_colorp pal_ptr;
+   png_const_colorp pal_ptr;

    png_byte buf[3];
 
    png_debug(1, "in png_write_PLTE");
 
    if ((
 #ifdef PNG_MNG_FEATURES_SUPPORTED
    png_byte buf[3];
 
    png_debug(1, "in png_write_PLTE");
 
    if ((
 #ifdef PNG_MNG_FEATURES_SUPPORTED

-        !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
+       !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&

 #endif
 #endif

-        num_pal == 0) || num_pal > 256)
+       num_pal == 0) || num_pal > 256)

    {
    {

-     if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
-     {
-        png_error(png_ptr, "Invalid number of colors in palette");
-     }
-     else
-     {
-        png_warning(png_ptr, "Invalid number of colors in palette");
-        return;
-     }
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         png_error(png_ptr, "Invalid number of colors in palette");
+      }
+
+      else
+      {
+         png_warning(png_ptr, "Invalid number of colors in palette");
+         return;
+      }

    }
 
    if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
    {
       png_warning(png_ptr,
    }
 
    if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
    {
       png_warning(png_ptr,

-        "Ignoring request to write a PLTE chunk in grayscale PNG");
+          "Ignoring request to write a PLTE chunk in grayscale PNG");
+

       return;
    }
 
    png_ptr->num_palette = (png_uint_16)num_pal;
    png_debug1(3, "num_palette = %d", png_ptr->num_palette);
 
       return;
    }
 
    png_ptr->num_palette = (png_uint_16)num_pal;
    png_debug1(3, "num_palette = %d", png_ptr->num_palette);
 

-   png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
-     (png_uint_32)(num_pal * 3));
+   png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));

 #ifdef PNG_POINTER_INDEXING_SUPPORTED
 #ifdef PNG_POINTER_INDEXING_SUPPORTED

+

    for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
    {
       buf[0] = pal_ptr->red;
    for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
    {
       buf[0] = pal_ptr->red;


@@ -639,11 +964,13 @@ png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
       buf[2] = pal_ptr->blue;
       png_write_chunk_data(png_ptr, buf, (png_size_t)3);
    }
       buf[2] = pal_ptr->blue;
       png_write_chunk_data(png_ptr, buf, (png_size_t)3);
    }

+

 #else
    /* This is a little slower but some buggy compilers need to do this
     * instead
     */
    pal_ptr=palette;
 #else
    /* This is a little slower but some buggy compilers need to do this
     * instead
     */
    pal_ptr=palette;

+

    for (i = 0; i < num_pal; i++)
    {
       buf[0] = pal_ptr[i].red;
    for (i = 0; i < num_pal; i++)
    {
       buf[0] = pal_ptr[i].red;


@@ -651,216 +978,278 @@ png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
       buf[2] = pal_ptr[i].blue;
       png_write_chunk_data(png_ptr, buf, (png_size_t)3);
    }
       buf[2] = pal_ptr[i].blue;
       png_write_chunk_data(png_ptr, buf, (png_size_t)3);
    }

+

 #endif
    png_write_chunk_end(png_ptr);
    png_ptr->mode |= PNG_HAVE_PLTE;
 }
 
 #endif
    png_write_chunk_end(png_ptr);
    png_ptr->mode |= PNG_HAVE_PLTE;
 }
 

-/* Write an IDAT chunk */
+/* This is similar to png_text_compress, above, except that it does not require
+ * all of the data at once and, instead of buffering the compressed result,
+ * writes it as IDAT chunks.  Unlike png_text_compress it *can* png_error out
+ * because it calls the write interface.  As a result it does its own error
+ * reporting and does not return an error code.  In the event of error it will
+ * just call png_error.  The input data length may exceed 32-bits.  The 'flush'
+ * parameter is exactly the same as that to deflate, with the following
+ * meanings:
+ *
+ * Z_NO_FLUSH: normal incremental output of compressed data
+ * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
+ * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
+ *
+ * The routine manages the acquire and release of the png_ptr->zstream by
+ * checking and (at the end) clearing png_ptr->zowner, it does some sanity
+ * checks on the 'mode' flags while doing this.
+ */

 void /* PRIVATE */
 void /* PRIVATE */

-png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
+png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
+   png_alloc_size_t input_len, int flush)

 {
 {

-   PNG_IDAT;
+   if (png_ptr->zowner != png_IDAT)
+   {
+      /* First time.   Ensure we have a temporary buffer for compression and
+       * trim the buffer list if it has more than one entry to free memory.
+       * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
+       * created at this point, but the check here is quick and safe.
+       */
+      if (png_ptr->zbuffer_list == NULL)
+      {
+         png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
+            png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+         png_ptr->zbuffer_list->next = NULL;
+      }
+
+      else
+         png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
+
+      /* It is a terminal error if we can't claim the zstream. */
+      if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
+         png_error(png_ptr, png_ptr->zstream.msg);

 
 

-   png_debug(1, "in png_write_IDAT");
+      /* The output state is maintained in png_ptr->zstream, so it must be
+       * initialized here after the claim.
+       */
+      png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
+      png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+   }

 
 

-   /* Optimize the CMF field in the zlib stream. */
-   /* This hack of the zlib stream is compliant to the stream specification. */
-   if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
-       png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+   /* Now loop reading and writing until all the input is consumed or an error
+    * terminates the operation.  The _out values are maintained across calls to
+    * this function, but the input must be reset each time.
+    */
+   png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+   png_ptr->zstream.avail_in = 0; /* set below */
+   for (;;)

    {
    {

-      unsigned int z_cmf = data[0];  /* zlib compression method and flags */
-      if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+      int ret;
+
+      /* INPUT: from the row data */
+      uInt avail = ZLIB_IO_MAX;
+
+      if (avail > input_len)
+         avail = (uInt)input_len; /* safe because of the check */
+
+      png_ptr->zstream.avail_in = avail;
+      input_len -= avail;
+
+      ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
+
+      /* Include as-yet unconsumed input */
+      input_len += png_ptr->zstream.avail_in;
+      png_ptr->zstream.avail_in = 0;
+
+      /* OUTPUT: write complete IDAT chunks when avail_out drops to zero, note
+       * that these two zstream fields are preserved across the calls, therefore
+       * there is no need to set these up on entry to the loop.
+       */
+      if (png_ptr->zstream.avail_out == 0)

       {
       {

-         /* Avoid memory underflows and multiplication overflows.
-          *
-          * The conditions below are practically always satisfied;
-          * however, they still must be checked.
+         png_bytep data = png_ptr->zbuffer_list->output;
+         uInt size = png_ptr->zbuffer_size;
+
+         /* Write an IDAT containing the data then reset the buffer.  The
+          * first IDAT may need deflate header optimization.

           */
           */

-         if (length >= 2 &&
-             png_ptr->height < 16384 && png_ptr->width < 16384)
+#        ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+            if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
+               png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+               optimize_cmf(data, png_image_size(png_ptr));
+#        endif
+
+         png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+         png_ptr->mode |= PNG_HAVE_IDAT;
+
+         png_ptr->zstream.next_out = data;
+         png_ptr->zstream.avail_out = size;
+
+         /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with
+          * the same flush parameter until it has finished output, for NO_FLUSH
+          * it doesn't matter.
+          */
+         if (ret == Z_OK && flush != Z_NO_FLUSH)
+            continue;
+      }
+
+      /* The order of these checks doesn't matter much; it just effect which
+       * possible error might be detected if multiple things go wrong at once.
+       */
+      if (ret == Z_OK) /* most likely return code! */
+      {
+         /* If all the input has been consumed then just return.  If Z_FINISH
+          * was used as the flush parameter something has gone wrong if we get
+          * here.
+          */
+         if (input_len == 0)

          {
          {

-            png_uint_32 uncompressed_idat_size = png_ptr->height *
-               ((png_ptr->width *
-               png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
-            unsigned int z_cinfo = z_cmf >> 4;
-            unsigned int half_z_window_size = 1 << (z_cinfo + 7);
-            while (uncompressed_idat_size <= half_z_window_size &&
-                   half_z_window_size >= 256)
-            {
-               z_cinfo--;
-               half_z_window_size >>= 1;
-            }
-            z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
-            if (data[0] != (png_byte)z_cmf)
-            {
-               data[0] = (png_byte)z_cmf;
-               data[1] &= 0xe0;
-               data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
-            }
+            if (flush == Z_FINISH)
+               png_error(png_ptr, "Z_OK on Z_FINISH with output space");
+
+            return;

          }
       }
          }
       }

+
+      else if (ret == Z_STREAM_END && flush == Z_FINISH)
+      {
+         /* This is the end of the IDAT data; any pending output must be
+          * flushed.  For small PNG files we may still be at the beginning.
+          */
+         png_bytep data = png_ptr->zbuffer_list->output;
+         uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
+
+#        ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+            if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
+               png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+               optimize_cmf(data, png_image_size(png_ptr));
+#        endif
+
+         png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+         png_ptr->zstream.avail_out = 0;
+         png_ptr->zstream.next_out = NULL;
+         png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
+
+         png_ptr->zowner = 0; /* Release the stream */
+         return;
+      }
+

       else
       else

-         png_error(png_ptr,
-            "Invalid zlib compression method or flags in IDAT");
+      {
+         /* This is an error condition. */
+         png_zstream_error(png_ptr, ret);
+         png_error(png_ptr, png_ptr->zstream.msg);
+      }

    }
    }

-
-   png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
-   png_ptr->mode |= PNG_HAVE_IDAT;

 }
 
 /* Write an IEND chunk */
 void /* PRIVATE */
 }
 
 /* Write an IEND chunk */
 void /* PRIVATE */

-png_write_IEND(png_structp png_ptr)
+png_write_IEND(png_structrp png_ptr)

 {
 {

-   PNG_IEND;
-

    png_debug(1, "in png_write_IEND");
 
    png_debug(1, "in png_write_IEND");
 

-   png_write_chunk(png_ptr, (png_bytep)png_IEND, NULL,
-     (png_size_t)0);
+   png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);

    png_ptr->mode |= PNG_HAVE_IEND;
 }
 
 #ifdef PNG_WRITE_gAMA_SUPPORTED
 /* Write a gAMA chunk */
    png_ptr->mode |= PNG_HAVE_IEND;
 }
 
 #ifdef PNG_WRITE_gAMA_SUPPORTED
 /* Write a gAMA chunk */

-#ifdef PNG_FLOATING_POINT_SUPPORTED
-void /* PRIVATE */
-png_write_gAMA(png_structp png_ptr, double file_gamma)
-{
-   PNG_gAMA;
-   png_uint_32 igamma;
-   png_byte buf[4];
-
-   png_debug(1, "in png_write_gAMA");
-
-   /* file_gamma is saved in 1/100,000ths */
-   igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
-   png_save_uint_32(buf, igamma);
-   png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
-}
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED

 void /* PRIVATE */
 void /* PRIVATE */

-png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
+png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)

 {
 {

-   PNG_gAMA;

    png_byte buf[4];
 
    png_debug(1, "in png_write_gAMA");
 
    /* file_gamma is saved in 1/100,000ths */
    png_save_uint_32(buf, (png_uint_32)file_gamma);
    png_byte buf[4];
 
    png_debug(1, "in png_write_gAMA");
 
    /* file_gamma is saved in 1/100,000ths */
    png_save_uint_32(buf, (png_uint_32)file_gamma);

-   png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
+   png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);

 }
 #endif
 }
 #endif

-#endif

 
 #ifdef PNG_WRITE_sRGB_SUPPORTED
 /* Write a sRGB chunk */
 void /* PRIVATE */
 
 #ifdef PNG_WRITE_sRGB_SUPPORTED
 /* Write a sRGB chunk */
 void /* PRIVATE */

-png_write_sRGB(png_structp png_ptr, int srgb_intent)
+png_write_sRGB(png_structrp png_ptr, int srgb_intent)

 {
 {

-   PNG_sRGB;

    png_byte buf[1];
 
    png_debug(1, "in png_write_sRGB");
 
    if (srgb_intent >= PNG_sRGB_INTENT_LAST)
    png_byte buf[1];
 
    png_debug(1, "in png_write_sRGB");
 
    if (srgb_intent >= PNG_sRGB_INTENT_LAST)

-         png_warning(png_ptr,
-            "Invalid sRGB rendering intent specified");
+      png_warning(png_ptr,
+          "Invalid sRGB rendering intent specified");
+

    buf[0]=(png_byte)srgb_intent;
    buf[0]=(png_byte)srgb_intent;

-   png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
+   png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);

 }
 #endif
 
 #ifdef PNG_WRITE_iCCP_SUPPORTED
 /* Write an iCCP chunk */
 void /* PRIVATE */
 }
 #endif
 
 #ifdef PNG_WRITE_iCCP_SUPPORTED
 /* Write an iCCP chunk */
 void /* PRIVATE */

-png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
-   png_charp profile, int profile_len)
+png_write_iCCP(png_structrp png_ptr, png_const_charp name,
+    png_const_bytep profile)

 {
 {

-   PNG_iCCP;
-   png_size_t name_len;
-   png_charp new_name;
+   png_uint_32 name_len;
+   png_uint_32 profile_len;
+   png_byte new_name[81]; /* 1 byte for the compression byte */

    compression_state comp;
    compression_state comp;

-   int embedded_profile_len = 0;

 
    png_debug(1, "in png_write_iCCP");
 
 
    png_debug(1, "in png_write_iCCP");
 

-   comp.num_output_ptr = 0;
-   comp.max_output_ptr = 0;
-   comp.output_ptr = NULL;
-   comp.input = NULL;
-   comp.input_len = 0;
-
-   if ((name_len = png_check_keyword(png_ptr, name,
-      &new_name)) == 0)
-      return;
+   /* These are all internal problems: the profile should have been checked
+    * before when it was stored.
+    */
+   if (profile == NULL)
+      png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */

 
 

-   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
-      png_warning(png_ptr, "Unknown compression type in iCCP chunk");
+   profile_len = png_get_uint_32(profile);

 
 

-   if (profile == NULL)
-      profile_len = 0;
+   if (profile_len < 132)
+      png_error(png_ptr, "ICC profile too short");

 
 

-   if (profile_len > 3)
-      embedded_profile_len =
-          ((*( (png_bytep)profile    ))<<24) |
-          ((*( (png_bytep)profile + 1))<<16) |
-          ((*( (png_bytep)profile + 2))<< 8) |
-          ((*( (png_bytep)profile + 3))    );
+   if (profile_len & 0x03)
+      png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");

 
 

-   if (embedded_profile_len < 0)

    {
    {

-      png_warning(png_ptr,
-        "Embedded profile length in iCCP chunk is negative");
-      png_free(png_ptr, new_name);
-      return;
-   }
+      png_uint_32 embedded_profile_len = png_get_uint_32(profile);

 
 

-   if (profile_len < embedded_profile_len)
-   {
-      png_warning(png_ptr,
-        "Embedded profile length too large in iCCP chunk");
-      png_free(png_ptr, new_name);
-      return;
+      if (profile_len != embedded_profile_len)
+         png_error(png_ptr, "Profile length does not match profile");

    }
 
    }
 

-   if (profile_len > embedded_profile_len)
-   {
-      png_warning(png_ptr,
-        "Truncating profile to actual length in iCCP chunk");
-      profile_len = embedded_profile_len;
-   }
+   name_len = png_check_keyword(png_ptr, name, new_name);
+
+   if (name_len == 0)
+      png_error(png_ptr, "iCCP: invalid keyword");

 
 

-   if (profile_len)
-      profile_len = png_text_compress(png_ptr, profile,
-        (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
+   new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;

 
    /* Make sure we include the NULL after the name and the compression type */
 
    /* Make sure we include the NULL after the name and the compression type */

-   png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
-          (png_uint_32)(name_len + profile_len + 2));
-   new_name[name_len + 1] = 0x00;
-   png_write_chunk_data(png_ptr, (png_bytep)new_name,
-     (png_size_t)(name_len + 2));
+   ++name_len;

 
 

-   if (profile_len)
-      png_write_compressed_data_out(png_ptr, &comp);
+   png_text_compress_init(&comp, profile, profile_len);
+
+   /* Allow for keyword terminator and compression byte */
+   if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
+      png_error(png_ptr, png_ptr->zstream.msg);
+
+   png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
+
+   png_write_chunk_data(png_ptr, new_name, name_len);
+
+   png_write_compressed_data_out(png_ptr, &comp);

 
    png_write_chunk_end(png_ptr);
 
    png_write_chunk_end(png_ptr);

-   png_free(png_ptr, new_name);

 }
 #endif
 
 #ifdef PNG_WRITE_sPLT_SUPPORTED
 /* Write a sPLT chunk */
 void /* PRIVATE */
 }
 #endif
 
 #ifdef PNG_WRITE_sPLT_SUPPORTED
 /* Write a sPLT chunk */
 void /* PRIVATE */

-png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
+png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)

 {
 {

-   PNG_sPLT;
-   png_size_t name_len;
-   png_charp new_name;
+   png_uint_32 name_len;
+   png_byte new_name[80];

    png_byte entrybuf[10];
    png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
    png_size_t palette_size = entry_size * spalette->nentries;
    png_byte entrybuf[10];
    png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
    png_size_t palette_size = entry_size * spalette->nentries;


@@ -871,15 +1260,19 @@ png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
 
    png_debug(1, "in png_write_sPLT");
 
 
    png_debug(1, "in png_write_sPLT");
 

-   if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
-      return;
+   name_len = png_check_keyword(png_ptr, spalette->name, new_name);
+
+   if (name_len == 0)
+      png_error(png_ptr, "sPLT: invalid keyword");

 
    /* Make sure we include the NULL after the name */
 
    /* Make sure we include the NULL after the name */

-   png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
-     (png_uint_32)(name_len + 2 + palette_size));
+   png_write_chunk_header(png_ptr, png_sPLT,
+       (png_uint_32)(name_len + 2 + palette_size));
+

    png_write_chunk_data(png_ptr, (png_bytep)new_name,
    png_write_chunk_data(png_ptr, (png_bytep)new_name,

-     (png_size_t)(name_len + 1));
-   png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);
+       (png_size_t)(name_len + 1));
+
+   png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);

 
    /* Loop through each palette entry, writing appropriately */
 #ifdef PNG_POINTER_INDEXING_SUPPORTED
 
    /* Loop through each palette entry, writing appropriately */
 #ifdef PNG_POINTER_INDEXING_SUPPORTED


@@ -887,57 +1280,59 @@ png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
    {
       if (spalette->depth == 8)
       {
    {
       if (spalette->depth == 8)
       {

-          entrybuf[0] = (png_byte)ep->red;
-          entrybuf[1] = (png_byte)ep->green;
-          entrybuf[2] = (png_byte)ep->blue;
-          entrybuf[3] = (png_byte)ep->alpha;
-          png_save_uint_16(entrybuf + 4, ep->frequency);
+         entrybuf[0] = (png_byte)ep->red;
+         entrybuf[1] = (png_byte)ep->green;
+         entrybuf[2] = (png_byte)ep->blue;
+         entrybuf[3] = (png_byte)ep->alpha;
+         png_save_uint_16(entrybuf + 4, ep->frequency);

       }
       }

+

       else
       {
       else
       {

-          png_save_uint_16(entrybuf + 0, ep->red);
-          png_save_uint_16(entrybuf + 2, ep->green);
-          png_save_uint_16(entrybuf + 4, ep->blue);
-          png_save_uint_16(entrybuf + 6, ep->alpha);
-          png_save_uint_16(entrybuf + 8, ep->frequency);
+         png_save_uint_16(entrybuf + 0, ep->red);
+         png_save_uint_16(entrybuf + 2, ep->green);
+         png_save_uint_16(entrybuf + 4, ep->blue);
+         png_save_uint_16(entrybuf + 6, ep->alpha);
+         png_save_uint_16(entrybuf + 8, ep->frequency);

       }
       }

-      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+
+      png_write_chunk_data(png_ptr, entrybuf, entry_size);

    }
 #else
    ep=spalette->entries;
    }
 #else
    ep=spalette->entries;

-   for (i=0; i>spalette->nentries; i++)
+   for (i = 0; i>spalette->nentries; i++)

    {
       if (spalette->depth == 8)
       {
    {
       if (spalette->depth == 8)
       {

-          entrybuf[0] = (png_byte)ep[i].red;
-          entrybuf[1] = (png_byte)ep[i].green;
-          entrybuf[2] = (png_byte)ep[i].blue;
-          entrybuf[3] = (png_byte)ep[i].alpha;
-          png_save_uint_16(entrybuf + 4, ep[i].frequency);
+         entrybuf[0] = (png_byte)ep[i].red;
+         entrybuf[1] = (png_byte)ep[i].green;
+         entrybuf[2] = (png_byte)ep[i].blue;
+         entrybuf[3] = (png_byte)ep[i].alpha;
+         png_save_uint_16(entrybuf + 4, ep[i].frequency);

       }
       }

+

       else
       {
       else
       {

-          png_save_uint_16(entrybuf + 0, ep[i].red);
-          png_save_uint_16(entrybuf + 2, ep[i].green);
-          png_save_uint_16(entrybuf + 4, ep[i].blue);
-          png_save_uint_16(entrybuf + 6, ep[i].alpha);
-          png_save_uint_16(entrybuf + 8, ep[i].frequency);
+         png_save_uint_16(entrybuf + 0, ep[i].red);
+         png_save_uint_16(entrybuf + 2, ep[i].green);
+         png_save_uint_16(entrybuf + 4, ep[i].blue);
+         png_save_uint_16(entrybuf + 6, ep[i].alpha);
+         png_save_uint_16(entrybuf + 8, ep[i].frequency);

       }
       }

-      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+
+      png_write_chunk_data(png_ptr, entrybuf, entry_size);

    }
 #endif
 
    png_write_chunk_end(png_ptr);
    }
 #endif
 
    png_write_chunk_end(png_ptr);

-   png_free(png_ptr, new_name);

 }
 #endif
 
 #ifdef PNG_WRITE_sBIT_SUPPORTED
 /* Write the sBIT chunk */
 void /* PRIVATE */
 }
 #endif
 
 #ifdef PNG_WRITE_sBIT_SUPPORTED
 /* Write the sBIT chunk */
 void /* PRIVATE */

-png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
+png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)

 {
 {

-   PNG_sBIT;

    png_byte buf[4];
    png_size_t size;
 
    png_byte buf[4];
    png_size_t size;
 


@@ -949,7 +1344,8 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
       png_byte maxbits;
 
       maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
       png_byte maxbits;
 
       maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :

-                png_ptr->usr_bit_depth);
+          png_ptr->usr_bit_depth);
+

       if (sbit->red == 0 || sbit->red > maxbits ||
           sbit->green == 0 || sbit->green > maxbits ||
           sbit->blue == 0 || sbit->blue > maxbits)
       if (sbit->red == 0 || sbit->red > maxbits ||
           sbit->green == 0 || sbit->green > maxbits ||
           sbit->blue == 0 || sbit->blue > maxbits)


@@ -957,11 +1353,13 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
          png_warning(png_ptr, "Invalid sBIT depth specified");
          return;
       }
          png_warning(png_ptr, "Invalid sBIT depth specified");
          return;
       }

+

       buf[0] = sbit->red;
       buf[1] = sbit->green;
       buf[2] = sbit->blue;
       size = 3;
    }
       buf[0] = sbit->red;
       buf[1] = sbit->green;
       buf[2] = sbit->blue;
       size = 3;
    }

+

    else
    {
       if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
    else
    {
       if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)


@@ -969,6 +1367,7 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
          png_warning(png_ptr, "Invalid sBIT depth specified");
          return;
       }
          png_warning(png_ptr, "Invalid sBIT depth specified");
          return;
       }

+

       buf[0] = sbit->gray;
       size = 1;
    }
       buf[0] = sbit->gray;
       size = 1;
    }


@@ -980,104 +1379,46 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
          png_warning(png_ptr, "Invalid sBIT depth specified");
          return;
       }
          png_warning(png_ptr, "Invalid sBIT depth specified");
          return;
       }

+

       buf[size++] = sbit->alpha;
    }
 
       buf[size++] = sbit->alpha;
    }
 

-   png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
+   png_write_complete_chunk(png_ptr, png_sBIT, buf, size);

 }
 #endif
 
 #ifdef PNG_WRITE_cHRM_SUPPORTED
 /* Write the cHRM chunk */
 }
 #endif
 
 #ifdef PNG_WRITE_cHRM_SUPPORTED
 /* Write the cHRM chunk */

-#ifdef PNG_FLOATING_POINT_SUPPORTED

 void /* PRIVATE */
 void /* PRIVATE */

-png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
-   double red_x, double red_y, double green_x, double green_y,
-   double blue_x, double blue_y)
+png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)

 {
 {

-   PNG_cHRM;
-   png_byte buf[32];
-
-   png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y,
-      int_green_x, int_green_y, int_blue_x, int_blue_y;
-
-   png_debug(1, "in png_write_cHRM");
-
-   int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5);
-   int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5);
-   int_red_x   = (png_uint_32)(red_x   * 100000.0 + 0.5);
-   int_red_y   = (png_uint_32)(red_y   * 100000.0 + 0.5);
-   int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5);
-   int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5);
-   int_blue_x  = (png_uint_32)(blue_x  * 100000.0 + 0.5);
-   int_blue_y  = (png_uint_32)(blue_y  * 100000.0 + 0.5);
-
-#ifdef PNG_CHECK_cHRM_SUPPORTED
-   if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y,
-      int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y))
-#endif
-   {
-      /* Each value is saved in 1/100,000ths */
-
-      png_save_uint_32(buf, int_white_x);
-      png_save_uint_32(buf + 4, int_white_y);
-
-      png_save_uint_32(buf + 8, int_red_x);
-      png_save_uint_32(buf + 12, int_red_y);
-
-      png_save_uint_32(buf + 16, int_green_x);
-      png_save_uint_32(buf + 20, int_green_y);
-
-      png_save_uint_32(buf + 24, int_blue_x);
-      png_save_uint_32(buf + 28, int_blue_y);
-
-      png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
-   }
-}
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
-void /* PRIVATE */
-png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
-   png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
-   png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
-   png_fixed_point blue_y)
-{
-   PNG_cHRM;

    png_byte buf[32];
 
    png_debug(1, "in png_write_cHRM");
 
    /* Each value is saved in 1/100,000ths */
    png_byte buf[32];
 
    png_debug(1, "in png_write_cHRM");
 
    /* Each value is saved in 1/100,000ths */

-#ifdef PNG_CHECK_cHRM_SUPPORTED
-   if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
-      green_x, green_y, blue_x, blue_y))
-#endif
-   {
-      png_save_uint_32(buf, (png_uint_32)white_x);
-      png_save_uint_32(buf + 4, (png_uint_32)white_y);
+   png_save_int_32(buf,      xy->whitex);
+   png_save_int_32(buf +  4, xy->whitey);

 
 

-      png_save_uint_32(buf + 8, (png_uint_32)red_x);
-      png_save_uint_32(buf + 12, (png_uint_32)red_y);
+   png_save_int_32(buf +  8, xy->redx);
+   png_save_int_32(buf + 12, xy->redy);

 
 

-      png_save_uint_32(buf + 16, (png_uint_32)green_x);
-      png_save_uint_32(buf + 20, (png_uint_32)green_y);
+   png_save_int_32(buf + 16, xy->greenx);
+   png_save_int_32(buf + 20, xy->greeny);

 
 

-      png_save_uint_32(buf + 24, (png_uint_32)blue_x);
-      png_save_uint_32(buf + 28, (png_uint_32)blue_y);
+   png_save_int_32(buf + 24, xy->bluex);
+   png_save_int_32(buf + 28, xy->bluey);

 
 

-      png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
-   }
+   png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);

 }
 #endif
 }
 #endif

-#endif

 
 #ifdef PNG_WRITE_tRNS_SUPPORTED
 /* Write the tRNS chunk */
 void /* PRIVATE */
 
 #ifdef PNG_WRITE_tRNS_SUPPORTED
 /* Write the tRNS chunk */
 void /* PRIVATE */

-png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_color_16p tran,
-   int num_trans, int color_type)
+png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
+    png_const_color_16p tran, int num_trans, int color_type)

 {
 {

-   PNG_tRNS;

    png_byte buf[6];
 
    png_debug(1, "in png_write_tRNS");
    png_byte buf[6];
 
    png_debug(1, "in png_write_tRNS");


@@ -1086,42 +1427,54 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_color_16p tran,
    {
       if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
       {
    {
       if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
       {

-         png_warning(png_ptr, "Invalid number of transparent colors specified");
+         png_app_warning(png_ptr,
+             "Invalid number of transparent colors specified");

          return;
       }
          return;
       }

+

       /* Write the chunk out as it is */
       /* Write the chunk out as it is */

-      png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans_alpha,
-        (png_size_t)num_trans);
+      png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
+         (png_size_t)num_trans);

    }
    }

+

    else if (color_type == PNG_COLOR_TYPE_GRAY)
    {
       /* One 16 bit value */
       if (tran->gray >= (1 << png_ptr->bit_depth))
       {
    else if (color_type == PNG_COLOR_TYPE_GRAY)
    {
       /* One 16 bit value */
       if (tran->gray >= (1 << png_ptr->bit_depth))
       {

-         png_warning(png_ptr,
-           "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+         png_app_warning(png_ptr,
+             "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+

          return;
       }
          return;
       }

+

       png_save_uint_16(buf, tran->gray);
       png_save_uint_16(buf, tran->gray);

-      png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
+      png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);

    }
    }

+

    else if (color_type == PNG_COLOR_TYPE_RGB)
    {
       /* Three 16 bit values */
       png_save_uint_16(buf, tran->red);
       png_save_uint_16(buf + 2, tran->green);
       png_save_uint_16(buf + 4, tran->blue);
    else if (color_type == PNG_COLOR_TYPE_RGB)
    {
       /* Three 16 bit values */
       png_save_uint_16(buf, tran->red);
       png_save_uint_16(buf + 2, tran->green);
       png_save_uint_16(buf + 4, tran->blue);

+#ifdef PNG_WRITE_16BIT_SUPPORTED

       if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
       if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))

+#else
+      if (buf[0] | buf[2] | buf[4])
+#endif

       {
       {

-         png_warning(png_ptr,
+         png_app_warning(png_ptr,

            "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
          return;
       }
            "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
          return;
       }

-      png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
+
+      png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);

    }
    }

+

    else
    {
    else
    {

-      png_warning(png_ptr, "Can't write tRNS with an alpha channel");
+      png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");

    }
 }
 #endif
    }
 }
 #endif


@@ -1129,9 +1482,8 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_color_16p tran,
 #ifdef PNG_WRITE_bKGD_SUPPORTED
 /* Write the background chunk */
 void /* PRIVATE */
 #ifdef PNG_WRITE_bKGD_SUPPORTED
 /* Write the background chunk */
 void /* PRIVATE */

-png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
+png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)

 {
 {

-   PNG_bKGD;

    png_byte buf[6];
 
    png_debug(1, "in png_write_bKGD");
    png_byte buf[6];
 
    png_debug(1, "in png_write_bKGD");


@@ -1148,32 +1500,43 @@ png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
          png_warning(png_ptr, "Invalid background palette index");
          return;
       }
          png_warning(png_ptr, "Invalid background palette index");
          return;
       }

+

       buf[0] = back->index;
       buf[0] = back->index;

-      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);

    }
    }

+

    else if (color_type & PNG_COLOR_MASK_COLOR)
    {
       png_save_uint_16(buf, back->red);
       png_save_uint_16(buf + 2, back->green);
       png_save_uint_16(buf + 4, back->blue);
    else if (color_type & PNG_COLOR_MASK_COLOR)
    {
       png_save_uint_16(buf, back->red);
       png_save_uint_16(buf + 2, back->green);
       png_save_uint_16(buf + 4, back->blue);

+#ifdef PNG_WRITE_16BIT_SUPPORTED

       if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
       if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))

+#else
+      if (buf[0] | buf[2] | buf[4])
+#endif

       {
          png_warning(png_ptr,
       {
          png_warning(png_ptr,

-           "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+             "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+

          return;
       }
          return;
       }

-      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
+
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);

    }
    }

+

    else
    {
       if (back->gray >= (1 << png_ptr->bit_depth))
       {
          png_warning(png_ptr,
    else
    {
       if (back->gray >= (1 << png_ptr->bit_depth))
       {
          png_warning(png_ptr,

-           "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+             "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+

          return;
       }
          return;
       }

+

       png_save_uint_16(buf, back->gray);
       png_save_uint_16(buf, back->gray);

-      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);

    }
 }
 #endif
    }
 }
 #endif


@@ -1181,9 +1544,8 @@ png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
 #ifdef PNG_WRITE_hIST_SUPPORTED
 /* Write the histogram */
 void /* PRIVATE */
 #ifdef PNG_WRITE_hIST_SUPPORTED
 /* Write the histogram */
 void /* PRIVATE */

-png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
+png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)

 {
 {

-   PNG_hIST;

    int i;
    png_byte buf[3];
 
    int i;
    png_byte buf[3];
 


@@ -1192,242 +1554,111 @@ png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
    if (num_hist > (int)png_ptr->num_palette)
    {
       png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
    if (num_hist > (int)png_ptr->num_palette)
    {
       png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,

-         png_ptr->num_palette);
+          png_ptr->num_palette);
+

       png_warning(png_ptr, "Invalid number of histogram entries specified");
       return;
    }
 
       png_warning(png_ptr, "Invalid number of histogram entries specified");
       return;
    }
 

-   png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
-     (png_uint_32)(num_hist * 2));
+   png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
+

    for (i = 0; i < num_hist; i++)
    {
       png_save_uint_16(buf, hist[i]);
       png_write_chunk_data(png_ptr, buf, (png_size_t)2);
    }
    for (i = 0; i < num_hist; i++)
    {
       png_save_uint_16(buf, hist[i]);
       png_write_chunk_data(png_ptr, buf, (png_size_t)2);
    }

-   png_write_chunk_end(png_ptr);
-}
-#endif
-
-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
-    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
-/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
- * and if invalid, correct the keyword rather than discarding the entire
- * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
- * length, forbids leading or trailing whitespace, multiple internal spaces,
- * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
- *
- * The new_key is allocated to hold the corrected keyword and must be freed
- * by the calling routine.  This avoids problems with trying to write to
- * static keywords without having to have duplicate copies of the strings.
- */
-png_size_t /* PRIVATE */
-png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
-{
-   png_size_t key_len;
-   png_charp kp, dp;
-   int kflag;
-   int kwarn=0;
-
-   png_debug(1, "in png_check_keyword");
-
-   *new_key = NULL;
-
-   if (key == NULL || (key_len = png_strlen(key)) == 0)
-   {
-      png_warning(png_ptr, "zero length keyword");
-      return ((png_size_t)0);
-   }
-
-   png_debug1(2, "Keyword to be checked is '%s'", key);
-
-   *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
-   if (*new_key == NULL)
-   {
-      png_warning(png_ptr, "Out of memory while procesing keyword");
-      return ((png_size_t)0);
-   }
-
-   /* Replace non-printing characters with a blank and print a warning */
-   for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
-   {
-      if ((png_byte)*kp < 0x20 ||
-         ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))
-      {
-#ifdef PNG_STDIO_SUPPORTED
-         char msg[40];
-
-         png_snprintf(msg, 40,
-           "invalid keyword character 0x%02X", (png_byte)*kp);
-         png_warning(png_ptr, msg);
-#else
-         png_warning(png_ptr, "invalid character in keyword");
-#endif
-         *dp = ' ';
-      }
-      else
-      {
-         *dp = *kp;
-      }
-   }
-   *dp = '\0';
-
-   /* Remove any trailing white space. */
-   kp = *new_key + key_len - 1;
-   if (*kp == ' ')
-   {
-      png_warning(png_ptr, "trailing spaces removed from keyword");
-
-      while (*kp == ' ')
-      {
-         *(kp--) = '\0';
-         key_len--;
-      }
-   }
-
-   /* Remove any leading white space. */
-   kp = *new_key;
-   if (*kp == ' ')
-   {
-      png_warning(png_ptr, "leading spaces removed from keyword");
-
-      while (*kp == ' ')
-      {
-         kp++;
-         key_len--;
-      }
-   }
-
-   png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
-
-   /* Remove multiple internal spaces. */
-   for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
-   {
-      if (*kp == ' ' && kflag == 0)
-      {
-         *(dp++) = *kp;
-         kflag = 1;
-      }
-      else if (*kp == ' ')
-      {
-         key_len--;
-         kwarn=1;
-      }
-      else
-      {
-         *(dp++) = *kp;
-         kflag = 0;
-      }
-   }
-   *dp = '\0';
-   if (kwarn)
-      png_warning(png_ptr, "extra interior spaces removed from keyword");
-
-   if (key_len == 0)
-   {
-      png_free(png_ptr, *new_key);
-      png_warning(png_ptr, "Zero length keyword");
-   }
-
-   if (key_len > 79)
-   {
-      png_warning(png_ptr, "keyword length must be 1 - 79 characters");
-      (*new_key)[79] = '\0';
-      key_len = 79;
-   }

 
 

-   return (key_len);
+   png_write_chunk_end(png_ptr);

 }
 #endif
 
 #ifdef PNG_WRITE_tEXt_SUPPORTED
 /* Write a tEXt chunk */
 void /* PRIVATE */
 }
 #endif
 
 #ifdef PNG_WRITE_tEXt_SUPPORTED
 /* Write a tEXt chunk */
 void /* PRIVATE */

-png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
-   png_size_t text_len)
+png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+    png_size_t text_len)

 {
 {

-   PNG_tEXt;
-   png_size_t key_len;
-   png_charp new_key;
+   png_uint_32 key_len;
+   png_byte new_key[80];

 
    png_debug(1, "in png_write_tEXt");
 
 
    png_debug(1, "in png_write_tEXt");
 

-   if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
-      return;
+   key_len = png_check_keyword(png_ptr, key, new_key);
+
+   if (key_len == 0)
+      png_error(png_ptr, "tEXt: invalid keyword");

 
    if (text == NULL || *text == '\0')
       text_len = 0;
 
    if (text == NULL || *text == '\0')
       text_len = 0;

+

    else
    else

-      text_len = png_strlen(text);
+      text_len = strlen(text);
+
+   if (text_len > PNG_UINT_31_MAX - (key_len+1))
+      png_error(png_ptr, "tEXt: text too long");

 
    /* Make sure we include the 0 after the key */
 
    /* Make sure we include the 0 after the key */

-   png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,
-      (png_uint_32)(key_len + text_len + 1));
+   png_write_chunk_header(png_ptr, png_tEXt,
+       (png_uint_32)/*checked above*/(key_len + text_len + 1));

    /*
     * We leave it to the application to meet PNG-1.0 requirements on the
     * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
     * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
     * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
     */
    /*
     * We leave it to the application to meet PNG-1.0 requirements on the
     * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
     * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
     * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
     */

-   png_write_chunk_data(png_ptr, (png_bytep)new_key,
-     (png_size_t)(key_len + 1));
+   png_write_chunk_data(png_ptr, new_key, key_len + 1);
+

    if (text_len)
    if (text_len)

-      png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);
+      png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);

 
    png_write_chunk_end(png_ptr);
 
    png_write_chunk_end(png_ptr);

-   png_free(png_ptr, new_key);

 }
 #endif
 
 #ifdef PNG_WRITE_zTXt_SUPPORTED
 /* Write a compressed text chunk */
 void /* PRIVATE */
 }
 #endif
 
 #ifdef PNG_WRITE_zTXt_SUPPORTED
 /* Write a compressed text chunk */
 void /* PRIVATE */

-png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
-   png_size_t text_len, int compression)
+png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+    png_size_t text_len, int compression)

 {
 {

-   PNG_zTXt;
-   png_size_t key_len;
-   char buf[1];
-   png_charp new_key;
+   png_uint_32 key_len;
+   png_byte new_key[81];

    compression_state comp;
 
    png_debug(1, "in png_write_zTXt");
    compression_state comp;
 
    png_debug(1, "in png_write_zTXt");

+   PNG_UNUSED(text_len) /* Always use strlen */

 
 

-   comp.num_output_ptr = 0;
-   comp.max_output_ptr = 0;
-   comp.output_ptr = NULL;
-   comp.input = NULL;
-   comp.input_len = 0;
-
-   if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
+   if (compression == PNG_TEXT_COMPRESSION_NONE)

    {
    {

-      png_free(png_ptr, new_key);
+      png_write_tEXt(png_ptr, key, text, 0);

       return;
    }
 
       return;
    }
 

-   if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
-   {
-      png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
-      png_free(png_ptr, new_key);
-      return;
-   }
+   if (compression != PNG_TEXT_COMPRESSION_zTXt)
+      png_error(png_ptr, "zTXt: invalid compression type");
+
+   key_len = png_check_keyword(png_ptr, key, new_key);
+
+   if (key_len == 0)
+      png_error(png_ptr, "zTXt: invalid keyword");

 
 

-   text_len = png_strlen(text);
+   /* Add the compression method and 1 for the keyword separator. */
+   new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+   ++key_len;

 
    /* Compute the compressed data; do it now for the length */
 
    /* Compute the compressed data; do it now for the length */

-   text_len = png_text_compress(png_ptr, text, text_len, compression,
-       &comp);
+   png_text_compress_init(&comp, (png_const_bytep)text,
+      text == NULL ? 0 : strlen(text));
+
+   if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
+      png_error(png_ptr, png_ptr->zstream.msg);

 
    /* Write start of chunk */
 
    /* Write start of chunk */

-   png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,
-     (png_uint_32)(key_len+text_len + 2));
+   png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
+

    /* Write key */
    /* Write key */

-   png_write_chunk_data(png_ptr, (png_bytep)new_key,
-     (png_size_t)(key_len + 1));
-   png_free(png_ptr, new_key);
+   png_write_chunk_data(png_ptr, new_key, key_len);

 
 

-   buf[0] = (png_byte)compression;
-   /* Write compression */
-   png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);

    /* Write the compressed data */
    png_write_compressed_data_out(png_ptr, &comp);
 
    /* Write the compressed data */
    png_write_compressed_data_out(png_ptr, &comp);
 


@@ -1439,97 +1670,109 @@ png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
 #ifdef PNG_WRITE_iTXt_SUPPORTED
 /* Write an iTXt chunk */
 void /* PRIVATE */
 #ifdef PNG_WRITE_iTXt_SUPPORTED
 /* Write an iTXt chunk */
 void /* PRIVATE */

-png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
-    png_charp lang, png_charp lang_key, png_charp text)
+png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
+    png_const_charp lang, png_const_charp lang_key, png_const_charp text)

 {
 {

-   PNG_iTXt;
-   png_size_t lang_len, key_len, lang_key_len, text_len;
-   png_charp new_lang;
-   png_charp new_key = NULL;
-   png_byte cbuf[2];
+   png_uint_32 key_len, prefix_len;
+   png_size_t lang_len, lang_key_len;
+   png_byte new_key[82];

    compression_state comp;
 
    png_debug(1, "in png_write_iTXt");
 
    compression_state comp;
 
    png_debug(1, "in png_write_iTXt");
 

-   comp.num_output_ptr = 0;
-   comp.max_output_ptr = 0;
-   comp.output_ptr = NULL;
-   comp.input = NULL;
+   key_len = png_check_keyword(png_ptr, key, new_key);

 
 

-   if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
-      return;
+   if (key_len == 0)
+      png_error(png_ptr, "iTXt: invalid keyword");

 
 

-   if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
+   /* Set the compression flag */
+   switch (compression)

    {
    {

-      png_warning(png_ptr, "Empty language field in iTXt chunk");
-      new_lang = NULL;
-      lang_len = 0;
+      case PNG_ITXT_COMPRESSION_NONE:
+      case PNG_TEXT_COMPRESSION_NONE:
+         compression = new_key[++key_len] = 0; /* no compression */
+         break;
+
+      case PNG_TEXT_COMPRESSION_zTXt:
+      case PNG_ITXT_COMPRESSION_zTXt:
+         compression = new_key[++key_len] = 1; /* compressed */
+         break;
+
+      default:
+         png_error(png_ptr, "iTXt: invalid compression");

    }
 
    }
 

-   if (lang_key == NULL)
-      lang_key_len = 0;
+   new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+   ++key_len; /* for the keywod separator */
+
+   /* We leave it to the application to meet PNG-1.0 requirements on the
+    * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
+    * any non-Latin-1 characters except for NEWLINE.  ISO PNG, however,
+    * specifies that the text is UTF-8 and this really doesn't require any
+    * checking.
+    *
+    * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+    *
+    * TODO: validate the language tag correctly (see the spec.)
+    */
+   if (lang == NULL) lang = ""; /* empty language is valid */
+   lang_len = strlen(lang)+1;
+   if (lang_key == NULL) lang_key = ""; /* may be empty */
+   lang_key_len = strlen(lang_key)+1;
+   if (text == NULL) text = ""; /* may be empty */
+
+   prefix_len = key_len;
+   if (lang_len > PNG_UINT_31_MAX-prefix_len)
+      prefix_len = PNG_UINT_31_MAX;

    else
    else

-      lang_key_len = png_strlen(lang_key);
+      prefix_len = (png_uint_32)(prefix_len + lang_len);

 
 

-   if (text == NULL)
-      text_len = 0;
+   if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
+      prefix_len = PNG_UINT_31_MAX;

    else
    else

-      text_len = png_strlen(text);
+      prefix_len = (png_uint_32)(prefix_len + lang_key_len);

 
 

-   /* Compute the compressed data; do it now for the length */
-   text_len = png_text_compress(png_ptr, text, text_len, compression-2,
-      &comp);
+   png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
+
+   if (compression)
+   {
+      if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
+         png_error(png_ptr, png_ptr->zstream.msg);
+   }
+
+   else
+   {
+      if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
+         png_error(png_ptr, "iTXt: uncompressed text too long");

 
 

+      /* So the string will fit in a chunk: */
+      comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
+   }

 
 

-   /* Make sure we include the compression flag, the compression byte,
-    * and the NULs after the key, lang, and lang_key parts */
+   png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);

 
 

-   png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
-          (png_uint_32)(
-        5 /* comp byte, comp flag, terminators for key, lang and lang_key */
-        + key_len
-        + lang_len
-        + lang_key_len
-        + text_len));
+   png_write_chunk_data(png_ptr, new_key, key_len);

 
 

-   /* We leave it to the application to meet PNG-1.0 requirements on the
-    * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
-    * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
-    * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
-    */
-   png_write_chunk_data(png_ptr, (png_bytep)new_key,
-     (png_size_t)(key_len + 1));
+   png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);

 
 

-   /* Set the compression flag */
-   if (compression == PNG_ITXT_COMPRESSION_NONE || \
-       compression == PNG_TEXT_COMPRESSION_NONE)
-       cbuf[0] = 0;
-   else /* compression == PNG_ITXT_COMPRESSION_zTXt */
-       cbuf[0] = 1;
-   /* Set the compression method */
-   cbuf[1] = 0;
-   png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
-
-   cbuf[0] = 0;
-   png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf),
-     (png_size_t)(lang_len + 1));
-   png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf),
-     (png_size_t)(lang_key_len + 1));
-   png_write_compressed_data_out(png_ptr, &comp);
+   png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
+
+   if (compression)
+      png_write_compressed_data_out(png_ptr, &comp);
+
+   else
+      png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.input_len);

 
    png_write_chunk_end(png_ptr);
 
    png_write_chunk_end(png_ptr);

-   png_free(png_ptr, new_key);
-   png_free(png_ptr, new_lang);

 }
 #endif
 
 #ifdef PNG_WRITE_oFFs_SUPPORTED
 /* Write the oFFs chunk */
 void /* PRIVATE */
 }
 #endif
 
 #ifdef PNG_WRITE_oFFs_SUPPORTED
 /* Write the oFFs chunk */
 void /* PRIVATE */

-png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
-   int unit_type)
+png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
+    int unit_type)

 {
 {

-   PNG_oFFs;

    png_byte buf[9];
 
    png_debug(1, "in png_write_oFFs");
    png_byte buf[9];
 
    png_debug(1, "in png_write_oFFs");


@@ -1541,63 +1784,67 @@ png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
    png_save_int_32(buf + 4, y_offset);
    buf[8] = (png_byte)unit_type;
 
    png_save_int_32(buf + 4, y_offset);
    buf[8] = (png_byte)unit_type;
 

-   png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
+   png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);

 }
 #endif
 #ifdef PNG_WRITE_pCAL_SUPPORTED
 /* Write the pCAL chunk (described in the PNG extensions document) */
 void /* PRIVATE */
 }
 #endif
 #ifdef PNG_WRITE_pCAL_SUPPORTED
 /* Write the pCAL chunk (described in the PNG extensions document) */
 void /* PRIVATE */

-png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
-   png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
+png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
+    png_int_32 X1, int type, int nparams, png_const_charp units,
+    png_charpp params)

 {
 {

-   PNG_pCAL;
-   png_size_t purpose_len, units_len, total_len;
-   png_uint_32p params_len;
+   png_uint_32 purpose_len;
+   png_size_t units_len, total_len;
+   png_size_tp params_len;

    png_byte buf[10];
    png_byte buf[10];

-   png_charp new_purpose;
+   png_byte new_purpose[80];

    int i;
 
    png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
 
    if (type >= PNG_EQUATION_LAST)
    int i;
 
    png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
 
    if (type >= PNG_EQUATION_LAST)

-      png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
+      png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
+
+   purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
+
+   if (purpose_len == 0)
+      png_error(png_ptr, "pCAL: invalid keyword");
+
+   ++purpose_len; /* terminator */

 
 

-   purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;

    png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
    png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);

-   units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
+   units_len = strlen(units) + (nparams == 0 ? 0 : 1);

    png_debug1(3, "pCAL units length = %d", (int)units_len);
    total_len = purpose_len + units_len + 10;
 
    png_debug1(3, "pCAL units length = %d", (int)units_len);
    total_len = purpose_len + units_len + 10;
 

-   params_len = (png_uint_32p)png_malloc(png_ptr,
-      (png_alloc_size_t)(nparams * png_sizeof(png_uint_32)));
+   params_len = (png_size_tp)png_malloc(png_ptr,
+       (png_alloc_size_t)(nparams * (sizeof (png_size_t))));

 
    /* Find the length of each parameter, making sure we don't count the
 
    /* Find the length of each parameter, making sure we don't count the

-      null terminator for the last parameter. */
+    * null terminator for the last parameter.
+    */

    for (i = 0; i < nparams; i++)
    {
    for (i = 0; i < nparams; i++)
    {

-      params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+      params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);

       png_debug2(3, "pCAL parameter %d length = %lu", i,
       png_debug2(3, "pCAL parameter %d length = %lu", i,

-        (unsigned long) params_len[i]);
-      total_len += (png_size_t)params_len[i];
+          (unsigned long)params_len[i]);
+      total_len += params_len[i];

    }
 
    png_debug1(3, "pCAL total length = %d", (int)total_len);
    }
 
    png_debug1(3, "pCAL total length = %d", (int)total_len);

-   png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
-   png_write_chunk_data(png_ptr, (png_bytep)new_purpose,
-     (png_size_t)purpose_len);
+   png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
+   png_write_chunk_data(png_ptr, new_purpose, purpose_len);

    png_save_int_32(buf, X0);
    png_save_int_32(buf + 4, X1);
    buf[8] = (png_byte)type;
    buf[9] = (png_byte)nparams;
    png_write_chunk_data(png_ptr, buf, (png_size_t)10);
    png_save_int_32(buf, X0);
    png_save_int_32(buf + 4, X1);
    buf[8] = (png_byte)type;
    buf[9] = (png_byte)nparams;
    png_write_chunk_data(png_ptr, buf, (png_size_t)10);

-   png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
-
-   png_free(png_ptr, new_purpose);
+   png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);

 
    for (i = 0; i < nparams; i++)
    {
 
    for (i = 0; i < nparams; i++)
    {

-      png_write_chunk_data(png_ptr, (png_bytep)params[i],
-         (png_size_t)params_len[i]);
+      png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);

    }
 
    png_free(png_ptr, params_len);
    }
 
    png_free(png_ptr, params_len);


@@ -1607,40 +1854,19 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
 
 #ifdef PNG_WRITE_sCAL_SUPPORTED
 /* Write the sCAL chunk */
 
 #ifdef PNG_WRITE_sCAL_SUPPORTED
 /* Write the sCAL chunk */

-#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
-void /* PRIVATE */
-png_write_sCAL(png_structp png_ptr, int unit, double width, double height)
-{
-   PNG_sCAL;
-   char buf[64];
-   png_size_t total_len;
-
-   png_debug(1, "in png_write_sCAL");
-
-   buf[0] = (char)unit;
-   png_snprintf(buf + 1, 63, "%12.12e", width);
-   total_len = 1 + png_strlen(buf + 1) + 1;
-   png_snprintf(buf + total_len, 64-total_len, "%12.12e", height);
-   total_len += png_strlen(buf + total_len);
-
-   png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
-   png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);
-}
-#else
-#ifdef PNG_FIXED_POINT_SUPPORTED

 void /* PRIVATE */
 void /* PRIVATE */

-png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
-   png_charp height)
+png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
+    png_const_charp height)

 {
 {

-   PNG_sCAL;

    png_byte buf[64];
    png_size_t wlen, hlen, total_len;
 
    png_debug(1, "in png_write_sCAL_s");
 
    png_byte buf[64];
    png_size_t wlen, hlen, total_len;
 
    png_debug(1, "in png_write_sCAL_s");
 

-   wlen = png_strlen(width);
-   hlen = png_strlen(height);
+   wlen = strlen(width);
+   hlen = strlen(height);

    total_len = wlen + hlen + 2;
    total_len = wlen + hlen + 2;

+

    if (total_len > 64)
    {
       png_warning(png_ptr, "Can't write sCAL (buffer too small)");
    if (total_len > 64)
    {
       png_warning(png_ptr, "Can't write sCAL (buffer too small)");


@@ -1648,24 +1874,21 @@ png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
    }
 
    buf[0] = (png_byte)unit;
    }
 
    buf[0] = (png_byte)unit;

-   png_memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
-   png_memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */
+   memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
+   memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */

 
    png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
 
    png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);

-   png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);
+   png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);

 }
 #endif
 }
 #endif

-#endif
-#endif

 
 #ifdef PNG_WRITE_pHYs_SUPPORTED
 /* Write the pHYs chunk */
 void /* PRIVATE */
 
 #ifdef PNG_WRITE_pHYs_SUPPORTED
 /* Write the pHYs chunk */
 void /* PRIVATE */

-png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
-   png_uint_32 y_pixels_per_unit,
-   int unit_type)
+png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
+    png_uint_32 y_pixels_per_unit,
+    int unit_type)

 {
 {

-   PNG_pHYs;

    png_byte buf[9];
 
    png_debug(1, "in png_write_pHYs");
    png_byte buf[9];
 
    png_debug(1, "in png_write_pHYs");


@@ -1677,7 +1900,7 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
    png_save_uint_32(buf + 4, y_pixels_per_unit);
    buf[8] = (png_byte)unit_type;
 
    png_save_uint_32(buf + 4, y_pixels_per_unit);
    buf[8] = (png_byte)unit_type;
 

-   png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
+   png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);

 }
 #endif
 
 }
 #endif
 


@@ -1686,9 +1909,8 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
  * or png_convert_from_time_t(), or fill in the structure yourself.
  */
 void /* PRIVATE */
  * or png_convert_from_time_t(), or fill in the structure yourself.
  */
 void /* PRIVATE */

-png_write_tIME(png_structp png_ptr, png_timep mod_time)
+png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)

 {
 {

-   PNG_tIME;

    png_byte buf[7];
 
    png_debug(1, "in png_write_tIME");
    png_byte buf[7];
 
    png_debug(1, "in png_write_tIME");


@@ -1708,48 +1930,53 @@ png_write_tIME(png_structp png_ptr, png_timep mod_time)
    buf[5] = mod_time->minute;
    buf[6] = mod_time->second;
 
    buf[5] = mod_time->minute;
    buf[6] = mod_time->second;
 

-   png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
+   png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);

 }
 #endif
 
 /* Initializes the row writing capability of libpng */
 void /* PRIVATE */
 }
 #endif
 
 /* Initializes the row writing capability of libpng */
 void /* PRIVATE */

-png_write_start_row(png_structp png_ptr)
+png_write_start_row(png_structrp png_ptr)

 {
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
 {
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */

-   int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};

 
    /* Offset to next interlace block */
 
    /* Offset to next interlace block */

-   int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};

 
    /* Start of interlace block in the y direction */
 
    /* Start of interlace block in the y direction */

-   int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};

 
    /* Offset to next interlace block in the y direction */
 
    /* Offset to next interlace block in the y direction */

-   int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};

 #endif
 
 #endif
 

-   png_size_t buf_size;
+   png_alloc_size_t buf_size;
+   int usr_pixel_depth;

 
    png_debug(1, "in png_write_start_row");
 
 
    png_debug(1, "in png_write_start_row");
 

-   buf_size = (png_size_t)(PNG_ROWBYTES(
-      png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
+   usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
+   buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
+
+   /* 1.5.6: added to allow checking in the row write code. */
+   png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
+   png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;

 
    /* Set up row buffer */
 
    /* Set up row buffer */

-   png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
-     (png_alloc_size_t)buf_size);
+   png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size);
+

    png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
 
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    /* Set up filtering buffer, if using this filter */
    if (png_ptr->do_filter & PNG_FILTER_SUB)
    {
    png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
 
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    /* Set up filtering buffer, if using this filter */
    if (png_ptr->do_filter & PNG_FILTER_SUB)
    {

-      png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
-         (png_alloc_size_t)(png_ptr->rowbytes + 1));
+      png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
+

       png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
    }
 
       png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
    }
 


@@ -1757,27 +1984,29 @@ png_write_start_row(png_structp png_ptr)
    if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
    {
       /* Set up previous row buffer */
    if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
    {
       /* Set up previous row buffer */

-      png_ptr->prev_row = (png_bytep)png_calloc(png_ptr,
-         (png_alloc_size_t)buf_size);
+      png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size);

 
       if (png_ptr->do_filter & PNG_FILTER_UP)
       {
          png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
 
       if (png_ptr->do_filter & PNG_FILTER_UP)
       {
          png_ptr->up_row = (png_bytep)png_malloc(png_ptr,

-            (png_size_t)(png_ptr->rowbytes + 1));
+            png_ptr->rowbytes + 1);
+

          png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
       }
 
       if (png_ptr->do_filter & PNG_FILTER_AVG)
       {
          png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
          png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
       }
 
       if (png_ptr->do_filter & PNG_FILTER_AVG)
       {
          png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,

-            (png_alloc_size_t)(png_ptr->rowbytes + 1));
+             png_ptr->rowbytes + 1);
+

          png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
       }
 
       if (png_ptr->do_filter & PNG_FILTER_PAETH)
       {
          png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
          png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
       }
 
       if (png_ptr->do_filter & PNG_FILTER_PAETH)
       {
          png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,

-            (png_size_t)(png_ptr->rowbytes + 1));
+             png_ptr->rowbytes + 1);
+

          png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
       }
    }
          png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
       }
    }


@@ -1790,48 +2019,47 @@ png_write_start_row(png_structp png_ptr)
       if (!(png_ptr->transformations & PNG_INTERLACE))
       {
          png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
       if (!(png_ptr->transformations & PNG_INTERLACE))
       {
          png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -

-            png_pass_ystart[0]) / png_pass_yinc[0];
+             png_pass_ystart[0]) / png_pass_yinc[0];
+

          png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
          png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -

-            png_pass_start[0]) / png_pass_inc[0];
+             png_pass_start[0]) / png_pass_inc[0];

       }
       }

+

       else
       {
          png_ptr->num_rows = png_ptr->height;
          png_ptr->usr_width = png_ptr->width;
       }
    }
       else
       {
          png_ptr->num_rows = png_ptr->height;
          png_ptr->usr_width = png_ptr->width;
       }
    }

+

    else
 #endif
    {
       png_ptr->num_rows = png_ptr->height;
       png_ptr->usr_width = png_ptr->width;
    }
    else
 #endif
    {
       png_ptr->num_rows = png_ptr->height;
       png_ptr->usr_width = png_ptr->width;
    }

-   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-   png_ptr->zstream.next_out = png_ptr->zbuf;

 }
 
 /* Internal use only.  Called when finished processing a row of data. */
 void /* PRIVATE */
 }
 
 /* Internal use only.  Called when finished processing a row of data. */
 void /* PRIVATE */

-png_write_finish_row(png_structp png_ptr)
+png_write_finish_row(png_structrp png_ptr)

 {
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
 {
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */

-   int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};

 
    /* Offset to next interlace block */
 
    /* Offset to next interlace block */

-   int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};

 
    /* Start of interlace block in the y direction */
 
    /* Start of interlace block in the y direction */

-   int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};

 
    /* Offset to next interlace block in the y direction */
 
    /* Offset to next interlace block in the y direction */

-   int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};

 #endif
 
 #endif
 

-   int ret;
-

    png_debug(1, "in png_write_finish_row");
 
    /* Next row */
    png_debug(1, "in png_write_finish_row");
 
    /* Next row */


@@ -1850,24 +2078,30 @@ png_write_finish_row(png_structp png_ptr)
       {
          png_ptr->pass++;
       }
       {
          png_ptr->pass++;
       }

+

       else
       {
          /* Loop until we find a non-zero width or height pass */
          do
          {
             png_ptr->pass++;
       else
       {
          /* Loop until we find a non-zero width or height pass */
          do
          {
             png_ptr->pass++;

+

             if (png_ptr->pass >= 7)
                break;
             if (png_ptr->pass >= 7)
                break;

+

             png_ptr->usr_width = (png_ptr->width +
             png_ptr->usr_width = (png_ptr->width +

-               png_pass_inc[png_ptr->pass] - 1 -
-               png_pass_start[png_ptr->pass]) /
-               png_pass_inc[png_ptr->pass];
+                png_pass_inc[png_ptr->pass] - 1 -
+                png_pass_start[png_ptr->pass]) /
+                png_pass_inc[png_ptr->pass];
+

             png_ptr->num_rows = (png_ptr->height +
             png_ptr->num_rows = (png_ptr->height +

-               png_pass_yinc[png_ptr->pass] - 1 -
-               png_pass_ystart[png_ptr->pass]) /
-               png_pass_yinc[png_ptr->pass];
+                png_pass_yinc[png_ptr->pass] - 1 -
+                png_pass_ystart[png_ptr->pass]) /
+                png_pass_yinc[png_ptr->pass];
+

             if (png_ptr->transformations & PNG_INTERLACE)
                break;
             if (png_ptr->transformations & PNG_INTERLACE)
                break;

+

          } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
 
       }
          } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
 
       }


@@ -1876,9 +2110,10 @@ png_write_finish_row(png_structp png_ptr)
       if (png_ptr->pass < 7)
       {
          if (png_ptr->prev_row != NULL)
       if (png_ptr->pass < 7)
       {
          if (png_ptr->prev_row != NULL)

-            png_memset(png_ptr->prev_row, 0,
-               (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
-               png_ptr->usr_bit_depth, png_ptr->width)) + 1);
+            memset(png_ptr->prev_row, 0,
+                (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
+                png_ptr->usr_bit_depth, png_ptr->width)) + 1);
+

          return;
       }
    }
          return;
       }
    }


@@ -1886,39 +2121,7 @@ png_write_finish_row(png_structp png_ptr)
 
    /* If we get here, we've just written the last row, so we need
       to flush the compressor */
 
    /* If we get here, we've just written the last row, so we need
       to flush the compressor */

-   do
-   {
-      /* Tell the compressor we are done */
-      ret = deflate(&png_ptr->zstream, Z_FINISH);
-      /* Check for an error */
-      if (ret == Z_OK)
-      {
-         /* Check to see if we need more room */
-         if (!(png_ptr->zstream.avail_out))
-         {
-            png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
-            png_ptr->zstream.next_out = png_ptr->zbuf;
-            png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-         }
-      }
-      else if (ret != Z_STREAM_END)
-      {
-         if (png_ptr->zstream.msg != NULL)
-            png_error(png_ptr, png_ptr->zstream.msg);
-         else
-            png_error(png_ptr, "zlib error");
-      }
-   } while (ret != Z_STREAM_END);
-
-   /* Write any extra space */
-   if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
-   {
-      png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
-         png_ptr->zstream.avail_out);
-   }
-
-   deflateReset(&png_ptr->zstream);
-   png_ptr->zstream.data_type = Z_BINARY;
+   png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);

 }
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
 }
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED


@@ -1935,10 +2138,10 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */

-   int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};

 
    /* Offset to next interlace block */
 
    /* Offset to next interlace block */

-   int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte  png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};

 
    png_debug(1, "in png_do_write_interlace");
 
 
    png_debug(1, "in png_do_write_interlace");
 


@@ -1961,6 +2164,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
             dp = row;
             d = 0;
             shift = 7;
             dp = row;
             d = 0;
             shift = 7;

+

             for (i = png_pass_start[pass]; i < row_width;
                i += png_pass_inc[pass])
             {
             for (i = png_pass_start[pass]; i < row_width;
                i += png_pass_inc[pass])
             {


@@ -1974,14 +2178,17 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
                   *dp++ = (png_byte)d;
                   d = 0;
                }
                   *dp++ = (png_byte)d;
                   d = 0;
                }

+

                else
                   shift--;
 
             }
             if (shift != 7)
                *dp = (png_byte)d;
                else
                   shift--;
 
             }
             if (shift != 7)
                *dp = (png_byte)d;

+

             break;
          }
             break;
          }

+

          case 2:
          {
             png_bytep sp;
          case 2:
          {
             png_bytep sp;


@@ -1995,6 +2202,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
             dp = row;
             shift = 6;
             d = 0;
             dp = row;
             shift = 6;
             d = 0;

+

             for (i = png_pass_start[pass]; i < row_width;
                i += png_pass_inc[pass])
             {
             for (i = png_pass_start[pass]; i < row_width;
                i += png_pass_inc[pass])
             {


@@ -2008,13 +2216,16 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
                   *dp++ = (png_byte)d;
                   d = 0;
                }
                   *dp++ = (png_byte)d;
                   d = 0;
                }

+

                else
                   shift -= 2;
             }
             if (shift != 6)
                else
                   shift -= 2;
             }
             if (shift != 6)

-                   *dp = (png_byte)d;
+               *dp = (png_byte)d;
+

             break;
          }
             break;
          }

+

          case 4:
          {
             png_bytep sp;
          case 4:
          {
             png_bytep sp;


@@ -2029,7 +2240,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
             shift = 4;
             d = 0;
             for (i = png_pass_start[pass]; i < row_width;
             shift = 4;
             d = 0;
             for (i = png_pass_start[pass]; i < row_width;

-               i += png_pass_inc[pass])
+                i += png_pass_inc[pass])

             {
                sp = row + (png_size_t)(i >> 1);
                value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
             {
                sp = row + (png_size_t)(i >> 1);
                value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;


@@ -2041,13 +2252,16 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
                   *dp++ = (png_byte)d;
                   d = 0;
                }
                   *dp++ = (png_byte)d;
                   d = 0;
                }

+

                else
                   shift -= 4;
             }
             if (shift != 4)
                *dp = (png_byte)d;
                else
                   shift -= 4;
             }
             if (shift != 4)
                *dp = (png_byte)d;

+

             break;
          }
             break;
          }

+

          default:
          {
             png_bytep sp;
          default:
          {
             png_bytep sp;


@@ -2058,18 +2272,21 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
 
             /* Start at the beginning */
             dp = row;
 
             /* Start at the beginning */
             dp = row;

+

             /* Find out how many bytes each pixel takes up */
             pixel_bytes = (row_info->pixel_depth >> 3);
             /* Find out how many bytes each pixel takes up */
             pixel_bytes = (row_info->pixel_depth >> 3);

-            /* Loop through the row, only looking at the pixels that
-               matter */
+
+            /* Loop through the row, only looking at the pixels that matter */

             for (i = png_pass_start[pass]; i < row_width;
                i += png_pass_inc[pass])
             {
                /* Find out where the original pixel is */
                sp = row + (png_size_t)i * pixel_bytes;
             for (i = png_pass_start[pass]; i < row_width;
                i += png_pass_inc[pass])
             {
                /* Find out where the original pixel is */
                sp = row + (png_size_t)i * pixel_bytes;

+

                /* Move the pixel */
                if (dp != sp)
                /* Move the pixel */
                if (dp != sp)

-                  png_memcpy(dp, sp, pixel_bytes);
+                  memcpy(dp, sp, pixel_bytes);
+

                /* Next pixel */
                dp += pixel_bytes;
             }
                /* Next pixel */
                dp += pixel_bytes;
             }


@@ -2078,11 +2295,12 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
       }
       /* Set new row width */
       row_info->width = (row_info->width +
       }
       /* Set new row width */
       row_info->width = (row_info->width +

-         png_pass_inc[pass] - 1 -
-         png_pass_start[pass]) /
-         png_pass_inc[pass];
-         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
-            row_info->width);
+          png_pass_inc[pass] - 1 -
+          png_pass_start[pass]) /
+          png_pass_inc[pass];
+
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+          row_info->width);

    }
 }
 #endif
    }
 }
 #endif


@@ -2091,21 +2309,24 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
  * been specified by the application, and then writes the row out with the
  * chosen filter.
  */
  * been specified by the application, and then writes the row out with the
  * chosen filter.
  */

+static void png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+   png_size_t row_bytes);
+

 #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
 #define PNG_HISHIFT 10
 #define PNG_LOMASK ((png_uint_32)0xffffL)
 #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
 void /* PRIVATE */
 #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
 #define PNG_HISHIFT 10
 #define PNG_LOMASK ((png_uint_32)0xffffL)
 #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
 void /* PRIVATE */

-png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
+png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)

 {
    png_bytep best_row;
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    png_bytep prev_row, row_buf;
    png_uint_32 mins, bpp;
    png_byte filter_to_do = png_ptr->do_filter;
 {
    png_bytep best_row;
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    png_bytep prev_row, row_buf;
    png_uint_32 mins, bpp;
    png_byte filter_to_do = png_ptr->do_filter;

-   png_uint_32 row_bytes = row_info->rowbytes;
+   png_size_t row_bytes = row_info->rowbytes;

 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED

-   int num_p_filters = (int)png_ptr->num_prev_filters;
+   int num_p_filters = png_ptr->num_prev_filters;

 #endif
 
    png_debug(1, "in png_write_find_filter");
 #endif
 
    png_debug(1, "in png_write_find_filter");


@@ -2113,8 +2334,8 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
 #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
   if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
   {
 #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
   if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
   {

-      /* These will never be selected so we need not test them. */
-      filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
+     /* These will never be selected so we need not test them. */
+     filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);

   }
 #endif
 
   }
 #endif
 


@@ -2140,11 +2361,14 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
     * computationally expensive).
     *
     * GRR 980525:  consider also
     * computationally expensive).
     *
     * GRR 980525:  consider also

+    *

     *   (1) minimum sum of absolute differences from running average (i.e.,
     *       keep running sum of non-absolute differences & count of bytes)
     *       [track dispersion, too?  restart average if dispersion too large?]
     *   (1) minimum sum of absolute differences from running average (i.e.,
     *       keep running sum of non-absolute differences & count of bytes)
     *       [track dispersion, too?  restart average if dispersion too large?]

+    *

     *  (1b) minimum sum of absolute differences from sliding average, probably
     *       with window size <= deflate window (usually 32K)
     *  (1b) minimum sum of absolute differences from sliding average, probably
     *       with window size <= deflate window (usually 32K)

+    *

     *   (2) minimum sum of squared differences from zero or running average
     *       (i.e., ~ root-mean-square approach)
     */
     *   (2) minimum sum of squared differences from zero or running average
     *       (i.e., ~ root-mean-square approach)
     */


@@ -2153,12 +2377,11 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    /* We don't need to test the 'no filter' case if this is the only filter
     * that has been chosen, as it doesn't actually do anything to the data.
     */
    /* We don't need to test the 'no filter' case if this is the only filter
     * that has been chosen, as it doesn't actually do anything to the data.
     */

-   if ((filter_to_do & PNG_FILTER_NONE) &&
-       filter_to_do != PNG_FILTER_NONE)
+   if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)

    {
       png_bytep rp;
       png_uint_32 sum = 0;
    {
       png_bytep rp;
       png_uint_32 sum = 0;

-      png_uint_32 i;
+      png_size_t i;

       int v;
 
       for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
       int v;
 
       for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)


@@ -2181,9 +2404,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                sumhi = (sumhi * png_ptr->filter_weights[j]) >>
                sumhi = (sumhi * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
             }
          }
 


@@ -2192,12 +2416,14 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
           * it has the minimum possible computational cost - none).
           */
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
           * it has the minimum possible computational cost - none).
           */
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;
 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;

+

          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }
          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }


@@ -2210,17 +2436,20 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    /* It's the only filter so no testing is needed */
    {
       png_bytep rp, lp, dp;
    /* It's the only filter so no testing is needed */
    {
       png_bytep rp, lp, dp;

-      png_uint_32 i;
+      png_size_t i;
+

       for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
            i++, rp++, dp++)
       {
          *dp = *rp;
       }
       for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
            i++, rp++, dp++)
       {
          *dp = *rp;
       }

+

       for (lp = row_buf + 1; i < row_bytes;
          i++, rp++, lp++, dp++)
       {
          *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
       }
       for (lp = row_buf + 1; i < row_bytes;
          i++, rp++, lp++, dp++)
       {
          *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
       }

+

       best_row = png_ptr->sub_row;
    }
 
       best_row = png_ptr->sub_row;
    }
 


@@ -2228,7 +2457,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    {
       png_bytep rp, dp, lp;
       png_uint_32 sum = 0, lmins = mins;
    {
       png_bytep rp, dp, lp;
       png_uint_32 sum = 0, lmins = mins;

-      png_uint_32 i;
+      png_size_t i;

       int v;
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       int v;
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED


@@ -2248,19 +2477,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;
 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;

+

          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }
          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }


@@ -2273,6 +2505,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
 
          sum += (v < 128) ? v : 256 - v;
       }
 
          sum += (v < 128) ? v : 256 - v;
       }

+

       for (lp = row_buf + 1; i < row_bytes;
          i++, rp++, lp++, dp++)
       {
       for (lp = row_buf + 1; i < row_bytes;
          i++, rp++, lp++, dp++)
       {


@@ -2297,19 +2530,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
             {
                sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
             {
                sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
                sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
             }
          }
 
          sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
          sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;
 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;

+

          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }
          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }


@@ -2326,14 +2562,15 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    if (filter_to_do == PNG_FILTER_UP)
    {
       png_bytep rp, dp, pp;
    if (filter_to_do == PNG_FILTER_UP)
    {
       png_bytep rp, dp, pp;

-      png_uint_32 i;
+      png_size_t i;

 
       for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
 
       for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,

-           pp = prev_row + 1; i < row_bytes;
-           i++, rp++, pp++, dp++)
+          pp = prev_row + 1; i < row_bytes;
+          i++, rp++, pp++, dp++)

       {
          *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
       }
       {
          *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
       }

+

       best_row = png_ptr->up_row;
    }
 
       best_row = png_ptr->up_row;
    }
 


@@ -2341,7 +2578,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    {
       png_bytep rp, dp, pp;
       png_uint_32 sum = 0, lmins = mins;
    {
       png_bytep rp, dp, pp;
       png_uint_32 sum = 0, lmins = mins;

-      png_uint_32 i;
+      png_size_t i;

       int v;
 
 
       int v;
 
 


@@ -2358,26 +2595,29 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;
 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;

+

          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }
 #endif
 
       for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }
 #endif
 
       for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,

-           pp = prev_row + 1; i < row_bytes; i++)
+          pp = prev_row + 1; i < row_bytes; i++)

       {
          v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
 
       {
          v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
 


@@ -2400,19 +2640,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                sumhi = (sumhi * png_ptr->filter_weights[j]) >>
                sumhi = (sumhi * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
             }
          }
 
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;
 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;

+

          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }
          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }


@@ -2430,11 +2673,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    {
       png_bytep rp, dp, pp, lp;
       png_uint_32 i;
    {
       png_bytep rp, dp, pp, lp;
       png_uint_32 i;

+

       for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
            pp = prev_row + 1; i < bpp; i++)
       {
          *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
       }
       for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
            pp = prev_row + 1; i < bpp; i++)
       {
          *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
       }

+

       for (lp = row_buf + 1; i < row_bytes; i++)
       {
          *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
       for (lp = row_buf + 1; i < row_bytes; i++)
       {
          *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))


@@ -2447,7 +2692,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    {
       png_bytep rp, dp, pp, lp;
       png_uint_32 sum = 0, lmins = mins;
    {
       png_bytep rp, dp, pp, lp;
       png_uint_32 sum = 0, lmins = mins;

-      png_uint_32 i;
+      png_size_t i;

       int v;
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       int v;
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED


@@ -2463,19 +2708,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;
 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;

+

          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }
          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }


@@ -2488,10 +2736,11 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
 
          sum += (v < 128) ? v : 256 - v;
       }
 
          sum += (v < 128) ? v : 256 - v;
       }

+

       for (lp = row_buf + 1; i < row_bytes; i++)
       {
          v = *dp++ =
       for (lp = row_buf + 1; i < row_bytes; i++)
       {
          v = *dp++ =

-          (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
+             (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);

 
          sum += (v < 128) ? v : 256 - v;
 
 
          sum += (v < 128) ? v : 256 - v;
 


@@ -2512,19 +2761,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                sumhi = (sumhi * png_ptr->filter_weights[j]) >>
                sumhi = (sumhi * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
             }
          }
 
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;
 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;

+

          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }
          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }


@@ -2541,9 +2793,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    if (filter_to_do == PNG_FILTER_PAETH)
    {
       png_bytep rp, dp, pp, cp, lp;
    if (filter_to_do == PNG_FILTER_PAETH)
    {
       png_bytep rp, dp, pp, cp, lp;

-      png_uint_32 i;
+      png_size_t i;
+

       for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
       for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,

-           pp = prev_row + 1; i < bpp; i++)
+          pp = prev_row + 1; i < bpp; i++)

       {
          *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
       }
       {
          *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
       }


@@ -2580,7 +2833,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    {
       png_bytep rp, dp, pp, cp, lp;
       png_uint_32 sum = 0, lmins = mins;
    {
       png_bytep rp, dp, pp, cp, lp;
       png_uint_32 sum = 0, lmins = mins;

-      png_uint_32 i;
+      png_size_t i;

       int v;
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       int v;
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED


@@ -2596,26 +2849,29 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
             {
                lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
                lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
             }
          }
 
          lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
          lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;
 
          if (lmhi > PNG_HIMASK)
             lmins = PNG_MAXSUM;

+

          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }
 #endif
 
       for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
          else
             lmins = (lmhi << PNG_HISHIFT) + lmlo;
       }
 #endif
 
       for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,

-           pp = prev_row + 1; i < bpp; i++)
+          pp = prev_row + 1; i < bpp; i++)

       {
          v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
 
       {
          v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
 


@@ -2648,10 +2904,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
          pa = abs(p - a);
          pb = abs(p - b);
          pc = abs(p - c);
          pa = abs(p - a);
          pb = abs(p - b);
          pc = abs(p - c);

+

          if (pa <= pb && pa <= pc)
             p = a;
          if (pa <= pb && pa <= pc)
             p = a;

+

          else if (pb <= pc)
             p = b;
          else if (pb <= pc)
             p = b;

+

          else
             p = c;
 #endif /* PNG_SLOW_PAETH */
          else
             p = c;
 #endif /* PNG_SLOW_PAETH */


@@ -2677,19 +2936,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>
             if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
             {
                sumlo = (sumlo * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;
+

                sumhi = (sumhi * png_ptr->filter_weights[j]) >>
                sumhi = (sumhi * png_ptr->filter_weights[j]) >>

-                  PNG_WEIGHT_SHIFT;
+                   PNG_WEIGHT_SHIFT;

             }
          }
 
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
             }
          }
 
          sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;
+

          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
          sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>

-            PNG_COST_SHIFT;
+             PNG_COST_SHIFT;

 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;
 
          if (sumhi > PNG_HIMASK)
             sum = PNG_MAXSUM;

+

          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }
          else
             sum = (sumhi << PNG_HISHIFT) + sumlo;
       }


@@ -2701,9 +2963,9 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
       }
    }
 #endif /* PNG_WRITE_FILTER_SUPPORTED */
       }
    }
 #endif /* PNG_WRITE_FILTER_SUPPORTED */

-   /* Do the actual writing of the filtered row data from the chosen filter. */

 
 

-   png_write_filtered_row(png_ptr, best_row);
+   /* Do the actual writing of the filtered row data from the chosen filter. */
+   png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);

 
 #ifdef PNG_WRITE_FILTER_SUPPORTED
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 
 #ifdef PNG_WRITE_FILTER_SUPPORTED
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED


@@ -2711,10 +2973,12 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
    if (png_ptr->num_prev_filters > 0)
    {
       int j;
    if (png_ptr->num_prev_filters > 0)
    {
       int j;

+

       for (j = 1; j < num_p_filters; j++)
       {
          png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
       }
       for (j = 1; j < num_p_filters; j++)
       {
          png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
       }

+

       png_ptr->prev_filters[j] = best_row[0];
    }
 #endif
       png_ptr->prev_filters[j] = best_row[0];
    }
 #endif


@@ -2723,42 +2987,15 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
 
 
 /* Do the actual writing of a previously filtered row. */
 
 
 /* Do the actual writing of a previously filtered row. */

-void /* PRIVATE */
-png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
+static void
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+   png_size_t full_row_length/*includes filter byte*/)

 {
    png_debug(1, "in png_write_filtered_row");
 
    png_debug1(2, "filter = %d", filtered_row[0]);
 {
    png_debug(1, "in png_write_filtered_row");
 
    png_debug1(2, "filter = %d", filtered_row[0]);

-   /* Set up the zlib input buffer */

 
 

-   png_ptr->zstream.next_in = filtered_row;
-   png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
-   /* Repeat until we have compressed all the data */
-   do
-   {
-      int ret; /* Return of zlib */
-
-      /* Compress the data */
-      ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
-      /* Check for compression errors */
-      if (ret != Z_OK)
-      {
-         if (png_ptr->zstream.msg != NULL)
-            png_error(png_ptr, png_ptr->zstream.msg);
-         else
-            png_error(png_ptr, "zlib error");
-      }
-
-      /* See if it is time to write another IDAT */
-      if (!(png_ptr->zstream.avail_out))
-      {
-         /* Write the IDAT and reset the zlib output buffer */
-         png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
-         png_ptr->zstream.next_out = png_ptr->zbuf;
-         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-      }
-   /* Repeat until all data has been compressed */
-   } while (png_ptr->zstream.avail_in);
+   png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);

 
    /* Swap the current and previous rows */
    if (png_ptr->prev_row != NULL)
 
    /* Swap the current and previous rows */
    if (png_ptr->prev_row != NULL)