Fixed a VC6 warning (hopefully)

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

diff --git a/src/png/pngrio.c b/src/png/pngrio.c
index a3b0de20e1215573980dafc60a550cea40729e66..7d2522f1f86e9ca7ee3c0478c9522fadb948c93d 100644 (file)
--- a/src/png/pngrio.c
+++ b/src/png/pngrio.c
@@ -1,9 +1,9 @@
 
 /* pngrio.c - functions for data input
  *
- * libpng 1.2.6 - August 15, 2004
+ * Last changed in libpng 1.2.13 November 13, 2006
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2004 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2006 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.)
  *
@@ -18,6 +18,8 @@
 #define PNG_INTERNAL
 #include "png.h"
 
+#if defined(PNG_READ_SUPPORTED)
+
 /* Read the data from whatever input you are using.  The default routine
    reads from a file pointer.  Note that this routine sometimes gets called
    with very small lengths, so you should implement some kind of simple
@@ -44,6 +46,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
    png_size_t check;
 
+   if(png_ptr == NULL) return;
    /* fread() returns 0 on error, so it is OK to store this in a png_size_t
     * instead of an int, which is what fread() actually returns.
     */
@@ -67,13 +70,14 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 #define NEAR_BUF_SIZE 1024
 #define MIN(a,b) (a <= b ? a : b)
 
-static void /* PRIVATE */
+static void PNGAPI
 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
    int check;
    png_byte *n_data;
    png_FILE_p io_ptr;
 
+   if(png_ptr == NULL) return;
    /* Check if data really is near. If so, use usual code. */
    n_data = (png_byte *)CVT_PTR_NOCHECK(data);
    io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
@@ -134,6 +138,7 @@ void PNGAPI
 png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
    png_rw_ptr read_data_fn)
 {
+   if(png_ptr == NULL) return;
    png_ptr->io_ptr = io_ptr;
 
 #if !defined(PNG_NO_STDIO)
@@ -159,3 +164,4 @@ png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
    png_ptr->output_flush_fn = NULL;
 #endif
 }
+#endif /* PNG_READ_SUPPORTED */