Imported from libpng-1.2.9beta9.tar
diff --git a/pngwrite.c b/pngwrite.c
index e7817f2..17d285b 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -1,7 +1,7 @@
/* pngwrite.c - general routines to write a PNG file
*
- * Last changed in libpng 1.2.9 March 9, 2006
+ * Last changed in libpng 1.2.9 March 10, 2006
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2006 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -26,6 +26,8 @@
png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_write_info_before_PLTE\n");
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
{
png_write_sig(png_ptr); /* write PNG signature */
@@ -128,6 +130,9 @@
png_debug(1, "in png_write_info\n");
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
png_write_info_before_PLTE(png_ptr, info_ptr);
if (info_ptr->valid & PNG_INFO_PLTE)
@@ -290,6 +295,8 @@
png_write_end(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_write_end\n");
+ if (png_ptr == NULL)
+ return;
if (!(png_ptr->mode & PNG_HAVE_IDAT))
png_error(png_ptr, "No IDATs written into file");
@@ -617,6 +624,10 @@
#ifdef PNG_SETJMP_SUPPORTED
jmp_buf tmp_jmp; /* to save current jump buffer */
#endif
+
+ if (png_ptr == NULL)
+ return;
+
int i = 0;
do
{
@@ -694,6 +705,10 @@
png_bytepp rp; /* row pointer */
png_debug(1, "in png_write_rows\n");
+
+ if (png_ptr == NULL)
+ return;
+
/* loop through the rows */
for (i = 0, rp = row; i < num_rows; i++, rp++)
{
@@ -711,6 +726,9 @@
int pass, num_pass; /* pass variables */
png_bytepp rp; /* points to current row */
+ if (png_ptr == NULL)
+ return;
+
png_debug(1, "in png_write_image\n");
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
/* intialize interlace handling. If image is not interlaced,
@@ -734,8 +752,11 @@
void PNGAPI
png_write_row(png_structp png_ptr, png_bytep row)
{
+ if (png_ptr == NULL)
+ return;
png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
png_ptr->row_number, png_ptr->pass);
+
/* initialize transformations and other stuff if first time */
if (png_ptr->row_number == 0 && png_ptr->pass == 0)
{
@@ -909,6 +930,8 @@
png_set_flush(png_structp png_ptr, int nrows)
{
png_debug(1, "in png_set_flush\n");
+ if (png_ptr == NULL)
+ return;
png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
}
@@ -919,6 +942,8 @@
int wrote_IDAT;
png_debug(1, "in png_write_flush\n");
+ if (png_ptr == NULL)
+ return;
/* We have already written out all of the data */
if (png_ptr->row_number >= png_ptr->num_rows)
return;
@@ -1095,6 +1120,8 @@
png_set_filter(png_structp png_ptr, int method, int filters)
{
png_debug(1, "in png_set_filter\n");
+ if (png_ptr == NULL)
+ return;
#if defined(PNG_MNG_FEATURES_SUPPORTED)
if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
(method == PNG_INTRAPIXEL_DIFFERENCING))
@@ -1203,6 +1230,8 @@
int i;
png_debug(1, "in png_set_filter_heuristics\n");
+ if (png_ptr == NULL)
+ return;
if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
{
png_warning(png_ptr, "Unknown filter heuristic method");
@@ -1315,6 +1344,8 @@
png_set_compression_level(png_structp png_ptr, int level)
{
png_debug(1, "in png_set_compression_level\n");
+ if (png_ptr == NULL)
+ return;
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
png_ptr->zlib_level = level;
}
@@ -1323,6 +1354,8 @@
png_set_compression_mem_level(png_structp png_ptr, int mem_level)
{
png_debug(1, "in png_set_compression_mem_level\n");
+ if (png_ptr == NULL)
+ return;
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
png_ptr->zlib_mem_level = mem_level;
}
@@ -1331,6 +1364,8 @@
png_set_compression_strategy(png_structp png_ptr, int strategy)
{
png_debug(1, "in png_set_compression_strategy\n");
+ if (png_ptr == NULL)
+ return;
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
png_ptr->zlib_strategy = strategy;
}
@@ -1338,6 +1373,8 @@
void PNGAPI
png_set_compression_window_bits(png_structp png_ptr, int window_bits)
{
+ if (png_ptr == NULL)
+ return;
if (window_bits > 15)
png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
else if (window_bits < 8)
@@ -1358,6 +1395,8 @@
png_set_compression_method(png_structp png_ptr, int method)
{
png_debug(1, "in png_set_compression_method\n");
+ if (png_ptr == NULL)
+ return;
if (method != 8)
png_warning(png_ptr, "Only compression method 8 is supported by PNG");
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
@@ -1367,6 +1406,8 @@
void PNGAPI
png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
{
+ if (png_ptr == NULL)
+ return;
png_ptr->write_row_fn = write_row_fn;
}
@@ -1376,6 +1417,8 @@
write_user_transform_fn)
{
png_debug(1, "in png_set_write_user_transform_fn\n");
+ if (png_ptr == NULL)
+ return;
png_ptr->transformations |= PNG_USER_TRANSFORM;
png_ptr->write_user_transform_fn = write_user_transform_fn;
}
@@ -1387,6 +1430,8 @@
png_write_png(png_structp png_ptr, png_infop info_ptr,
int transforms, voidp params)
{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
/* invert the alpha channel from opacity to transparency */
if (transforms & PNG_TRANSFORM_INVERT_ALPHA)