[devel] Re-initialize the zlib compressor before compressing non-IDAT chunks.

1 files changed, 15 insertions, 6 deletions

diff --git a/pngmem.c b/pngmem.c
index a15d8b085..487c96bec 100644
--- a/pngmem.c
+++ b/pngmem.c
@@ -187,8 +187,9 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
             int num_blocks;
             png_uint_32 total_size;
             png_bytep table;
-            int i;
+            int i, mem_level, window_bits;
             png_byte huge * hptr;
+            int window_bits
 
             if (ret != NULL)
             {
@@ -196,14 +197,22 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
                ret = NULL;
             }
 
-            if (png_ptr->zlib_window_bits > 14)
-               num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
+            window_bits =
+                png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ?
+                png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits;
+
+            if (window_bits > 14)
+               num_blocks = (int)(1 << (window_bits - 14));
 
             else
                num_blocks = 1;
 
-            if (png_ptr->zlib_mem_level >= 7)
-               num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
+            mem_level =
+                png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ?
+                png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level;
+
+            if (mem_level >= 7)
+               num_blocks += (int)(1 << (mem_level - 7));
 
             else
                num_blocks++;
@@ -277,7 +286,7 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
       {
 #  ifndef PNG_USER_MEM_SUPPORTED
          if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-            png_error(png_ptr, "Out of Memory"); /* Note "o" and "M" */
+            png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */
 
          else
             png_warning(png_ptr, "Out of Memory");