Fixed a VC6 warning (hopefully)

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

diff --git a/src/png/pngwio.c b/src/png/pngwio.c
index f356b7d4a756010aadedda0e96f951d0df48f6a7..371a4fad624b8b57fa94a876b52fb9ff95c135d3 100644 (file)
--- a/src/png/pngwio.c
+++ b/src/png/pngwio.c
@@ -1,9 +1,9 @@
 
 /* pngwio.c - functions for data output
  *
- * libpng 1.2.4 - July 8, 2002
+ * Last changed in libpng 1.2.13 November 13, 2006
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2002 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.)
  *
@@ -45,6 +45,7 @@ png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
    png_uint_32 check;
 
+   if(png_ptr == NULL) return;
 #if defined(_WIN32_WCE)
    if ( !WriteFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
       check = 0;
@@ -70,6 +71,7 @@ png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
    png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
    png_FILE_p io_ptr;
 
+   if(png_ptr == NULL) return;
    /* Check if data really is near. If so, use usual code. */
    near_data = (png_byte *)CVT_PTR_NOCHECK(data);
    io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
@@ -131,6 +133,9 @@ png_default_flush(png_structp png_ptr)
 {
 #if !defined(_WIN32_WCE)
    png_FILE_p io_ptr;
+#endif
+   if(png_ptr == NULL) return;
+#if !defined(_WIN32_WCE)
    io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
    if (io_ptr != NULL)
       fflush(io_ptr);
@@ -165,6 +170,7 @@ void PNGAPI
 png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
 {
+   if(png_ptr == NULL) return;
    png_ptr->io_ptr = io_ptr;
 
 #if !defined(PNG_NO_STDIO)