fixed wrong assert

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

diff --git a/src/png/pngwio.c b/src/png/pngwio.c
index 69825046917a684b23cfa9cef54e4834482586c4..84b5b2869d8053e2e864b4ffd1696d595732fa99 100644 (file)
--- a/src/png/pngwio.c
+++ b/src/png/pngwio.c
@@ -1,29 +1,28 @@
 
 /* pngwio.c - functions for data output
  *
- * libpng 1.0.1
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * March 15, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
- * This file provides a location for all output.  Users which need
- * special handling are expected to write functions which have the same
- * arguments as these, and perform similar functions, but possibly use
- * different output methods.  Note that you shouldn't change these
+ * This file provides a location for all output.  Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods.  Note that you shouldn't change these
  * functions, but rather write replacement functions and then change
  * them at run time with png_set_write_fn(...).
  */
 
 #define PNG_INTERNAL
-#include "../png/png.h"
+#include "png.h"
 
 /* Write the data to whatever output you are using.  The default routine
    writes to a file pointer.  Note that this routine sometimes gets called
    with very small lengths, so you should implement some kind of simple
    buffering if you are using unbuffered writes.  This should never be asked
-   to write more then 64K on a 16 bit machine.  */
+   to write more than 64K on a 16 bit machine.  */
 
 void
 png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
@@ -35,7 +34,7 @@ png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
 }
 
 #if !defined(PNG_NO_STDIO)
-/* This is the function which does the actual writing of data.  If you are
+/* This is the function that does the actual writing of data.  If you are
    not writing to a standard C stream, you should create a replacement
    write_data function and use it at run time with png_set_write_fn(), rather
    than changing the library. */
@@ -133,13 +132,13 @@ png_default_flush(png_structp png_ptr)
    png_ptr       - pointer to a png output data structure
    io_ptr        - pointer to user supplied structure containing info about
                    the output functions.  May be NULL.
-   write_data_fn - pointer to a new output function which takes as its
+   write_data_fn - pointer to a new output function that takes as its
                    arguments a pointer to a png_struct, a pointer to
-                   data to be written, and a 32-bit unsigned int which is
+                   data to be written, and a 32-bit unsigned int that is
                    the number of bytes to be written.  The new write
                    function should call png_error(png_ptr, "Error msg")
                    to exit and output any fatal error messages.
-   flush_data_fn - pointer to a new flush function which takes as its
+   flush_data_fn - pointer to a new flush function that takes as its
                    arguments a pointer to a png_struct.  After a call to
                    the flush function, there should be no data in any buffers
                    or pending transmission.  If the output method doesn't do
@@ -175,14 +174,21 @@ png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 
    /* It is an error to read while writing a png file */
-   png_ptr->read_data_fn = NULL;
+   if (png_ptr->read_data_fn != NULL)
+   {
+      png_ptr->read_data_fn = NULL;
+      png_warning(png_ptr,
+         "Attempted to set both read_data_fn and write_data_fn in");
+      png_warning(png_ptr,
+         "the same structure.  Resetting read_data_fn to NULL.");
+   }
 }
 
-#if defined(USE_FAR_KEYWORD) 
-#if defined(_MSC_VER)   
+#if defined(USE_FAR_KEYWORD)
+#if defined(_MSC_VER)
 void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 {
-   void *near_ptr;   
+   void *near_ptr;
    void FAR *far_ptr;
    FP_OFF(near_ptr) = FP_OFF(ptr);
    far_ptr = (void FAR *)near_ptr;
@@ -194,7 +200,7 @@ void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 #  else
 void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 {
-   void *near_ptr;   
+   void *near_ptr;
    void FAR *far_ptr;
    near_ptr = (void FAR *)ptr;
    far_ptr = (void FAR *)near_ptr;