Update libpng to 1.2.33.

third_party/libpng/pngpread.c

 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.32 [September 18, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 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.)
  */
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 
 /* push model modes */
 #define PNG_READ_SIG_MODE   0
 #define PNG_READ_CHUNK_MODE 1
 #define PNG_READ_IDAT_MODE  2
 #define PNG_SKIP_MODE       3
 #define PNG_READ_tEXt_MODE  4
 #define PNG_READ_zTXt_MODE  5
 #define PNG_READ_DONE_MODE  6
 #define PNG_READ_iTXt_MODE  7
 #define PNG_ERROR_MODE      8
 
 void PNGAPI
 png_process_data(png_structp png_ptr, png_infop info_ptr,
    png_bytep buffer, png_size_t buffer_size)
 {
-   if(png_ptr == NULL || info_ptr == NULL) return;
+   if (png_ptr == NULL || info_ptr == NULL) return;
    png_push_restore_buffer(png_ptr, buffer, buffer_size);
 
    while (png_ptr->buffer_size)
    {
       png_process_some_data(png_ptr, info_ptr);
    }
 }
 
 /* What we do with the incoming data depends on what we were previously
  * doing before we ran out of data...
  */
 void /* PRIVATE */
 png_process_some_data(png_structp png_ptr, png_infop info_ptr)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    switch (png_ptr->process_mode)
    {
       case PNG_READ_SIG_MODE:
       {
          png_push_read_sig(png_ptr, info_ptr);
          break;
       }
       case PNG_READ_CHUNK_MODE:
       {
          png_push_read_chunk(png_ptr, info_ptr);
@@ skipping 50 matching lines @@
    png_size_t num_checked = png_ptr->sig_bytes,
              num_to_check = 8 - num_checked;
 
    if (png_ptr->buffer_size < num_to_check)
    {
       num_to_check = png_ptr->buffer_size;
    }
 
    png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
       num_to_check);
-   png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
+   png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
 
    if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
    {
       if (num_checked < 4 &&
           png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
          png_error(png_ptr, "Not a PNG file");
       else
          png_error(png_ptr, "PNG file corrupted by ASCII conversion");
    }
    else
@@ skipping 75 matching lines @@
    {
       png_byte chunk_length[4];
 
       if (png_ptr->buffer_size < 8)
       {
          png_push_save_buffer(png_ptr);
          return;
       }
 
       png_push_fill_buffer(png_ptr, chunk_length, 4);
-      png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
    }
 
    if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
-     if(png_ptr->mode & PNG_AFTER_IDAT)
+     if (png_ptr->mode & PNG_AFTER_IDAT)
         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
    if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
    {
+      if (png_ptr->push_length != 13)
+         png_error(png_ptr, "Invalid IHDR length");
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
-         if (png_ptr->push_length != 13)
-            png_error(png_ptr, "Invalid IHDR length");
          png_push_save_buffer(png_ptr);
          return;
       }
       png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
    }
    else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
          png_push_save_buffer(png_ptr);
@@ skipping 319 matching lines @@
       png_crc_finish(png_ptr, 0);
       png_ptr->process_mode = PNG_READ_CHUNK_MODE;
    }
 }
 
 void PNGAPI
 png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
 {
    png_bytep ptr;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    ptr = buffer;
    if (png_ptr->save_buffer_size)
    {
       png_size_t save_size;
 
       if (length < png_ptr->save_buffer_size)
          save_size = length;
       else
          save_size = png_ptr->save_buffer_size;
 
@@ skipping 20 matching lines @@
    }
 }
 
 void /* PRIVATE */
 png_push_save_buffer(png_structp png_ptr)
 {
    if (png_ptr->save_buffer_size)
    {
       if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
       {
-         png_size_t i,istop;
+         png_size_t i, istop;
          png_bytep sp;
          png_bytep dp;
 
          istop = png_ptr->save_buffer_size;
          for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
             i < istop; i++, sp++, dp++)
          {
             *dp = *sp;
          }
       }
@@ skipping 48 matching lines @@
    {
       png_byte chunk_length[4];
 
       if (png_ptr->buffer_size < 8)
       {
          png_push_save_buffer(png_ptr);
          return;
       }
 
       png_push_fill_buffer(png_ptr, chunk_length, 4);
-      png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
 
       if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
       {
          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
          if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
             png_error(png_ptr, "Not enough compressed data");
          return;
       }
 
       png_ptr->idat_size = png_ptr->push_length;
    }
    if (png_ptr->idat_size && png_ptr->save_buffer_size)
    {
       png_size_t save_size;
 
       if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
       {
          save_size = (png_size_t)png_ptr->idat_size;
          /* check for overflow */
-         if((png_uint_32)save_size != png_ptr->idat_size)
+         if ((png_uint_32)save_size != png_ptr->idat_size)
             png_error(png_ptr, "save_size overflowed in pngpread");
       }
       else
          save_size = png_ptr->save_buffer_size;
 
       png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
       if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
          png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
       png_ptr->idat_size -= save_size;
       png_ptr->buffer_size -= save_size;
       png_ptr->save_buffer_size -= save_size;
       png_ptr->save_buffer_ptr += save_size;
    }
    if (png_ptr->idat_size && png_ptr->current_buffer_size)
    {
       png_size_t save_size;
 
       if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
       {
          save_size = (png_size_t)png_ptr->idat_size;
          /* check for overflow */
-         if((png_uint_32)save_size != png_ptr->idat_size)
+         if ((png_uint_32)save_size != png_ptr->idat_size)
             png_error(png_ptr, "save_size overflowed in pngpread");
       }
       else
          save_size = png_ptr->current_buffer_size;
 
       png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
       if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
         png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
 
       png_ptr->idat_size -= save_size;
@@ skipping 19 matching lines @@
 png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
    png_size_t buffer_length)
 {
    int ret;
 
    if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
       png_error(png_ptr, "Extra compression data");
 
    png_ptr->zstream.next_in = buffer;
    png_ptr->zstream.avail_in = (uInt)buffer_length;
-   for(;;)
+   for (;;)
    {
       ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
       if (ret != Z_OK)
       {
          if (ret == Z_STREAM_END)
          {
             if (png_ptr->zstream.avail_in)
                png_error(png_ptr, "Extra compressed data");
             if (!(png_ptr->zstream.avail_out))
             {
@@ skipping 239 matching lines @@
    if (png_ptr->row_number < png_ptr->num_rows)
       return;
 
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
       png_memset_check(png_ptr, png_ptr->prev_row, 0,
          png_ptr->rowbytes + 1);
       do
       {
-         int pass;
-         pass = png_ptr->pass;
-         pass++;
-         if ((pass == 1 && png_ptr->width < 5) ||
-             (pass == 3 && png_ptr->width < 3) ||
-             (pass == 5 && png_ptr->width < 2))
-           pass++;
+         png_ptr->pass++;
+         if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+             (png_ptr->pass == 3 && png_ptr->width < 3) ||
+             (png_ptr->pass == 5 && png_ptr->width < 2))
+           png_ptr->pass++;
 
-         if (pass > 7)
-            pass--;
-         png_ptr->pass = (png_byte) pass;
-         if (pass < 7)
-           {
-             png_ptr->iwidth = (png_ptr->width +
-                png_pass_inc[pass] - 1 -
-                png_pass_start[pass]) /
-                png_pass_inc[pass];
+         if (png_ptr->pass > 7)
+            png_ptr->pass--;
+         if (png_ptr->pass >= 7)
+            break;
 
-             png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
-                png_ptr->iwidth) + 1;
+         png_ptr->iwidth = (png_ptr->width +
+            png_pass_inc[png_ptr->pass] - 1 -
+            png_pass_start[png_ptr->pass]) /
+            png_pass_inc[png_ptr->pass];
 
-             if (png_ptr->transformations & PNG_INTERLACE)
-                break;
+         png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
+            png_ptr->iwidth) + 1;
 
-             png_ptr->num_rows = (png_ptr->height +
-                png_pass_yinc[pass] - 1 -
-                png_pass_ystart[pass]) /
-                png_pass_yinc[pass];
-           }
-         else
-           break;
+         if (png_ptr->transformations & PNG_INTERLACE)
+            break;
+
+         png_ptr->num_rows = (png_ptr->height +
+            png_pass_yinc[png_ptr->pass] - 1 -
+            png_pass_ystart[png_ptr->pass]) /
+            png_pass_yinc[png_ptr->pass];
 
       } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
    }
 }
 
 #if defined(PNG_READ_tEXt_SUPPORTED)
 void /* PRIVATE */
 png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    length)
 {
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
       {
          png_error(png_ptr, "Out of place tEXt");
          info_ptr = info_ptr; /* to quiet some compiler warnings */
       }
 
 #ifdef PNG_MAX_MALLOC_64K
    png_ptr->skip_length = 0;  /* This may not be necessary */
 
    if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
    {
       png_warning(png_ptr, "tEXt chunk too large to fit in memory");
       png_ptr->skip_length = length - (png_uint_32)65535L;
       length = (png_uint_32)65535L;
    }
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-         (png_uint_32)(length+1));
+      (png_uint_32)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
    png_ptr->current_text_left = (png_size_t)length;
    png_ptr->process_mode = PNG_READ_tEXt_MODE;
 }
 
 void /* PRIVATE */
 png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
 {
@@ skipping 77 matching lines @@
     */
    if (length > (png_uint_32)65535L)
    {
       png_warning(png_ptr, "zTXt chunk too large to fit in memory");
       png_push_crc_skip(png_ptr, length);
       return;
    }
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-       (png_uint_32)(length+1));
+      (png_uint_32)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
    png_ptr->current_text_left = (png_size_t)length;
    png_ptr->process_mode = PNG_READ_zTXt_MODE;
 }
 
 void /* PRIVATE */
 png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
 {
@@ skipping 70 matching lines @@
             png_ptr->current_text = NULL;
             png_free(png_ptr, key);
             png_free(png_ptr, text);
             return;
          }
          if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
          {
             if (text == NULL)
             {
                text = (png_charp)png_malloc(png_ptr,
-                  (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
-                     + key_size + 1));
+                     (png_uint_32)(png_ptr->zbuf_size
+                     - png_ptr->zstream.avail_out + key_size + 1));
                png_memcpy(text + key_size, png_ptr->zbuf,
                   png_ptr->zbuf_size - png_ptr->zstream.avail_out);
                png_memcpy(text, key, key_size);
                text_size = key_size + png_ptr->zbuf_size -
                   png_ptr->zstream.avail_out;
                *(text + text_size) = '\0';
             }
             else
             {
                png_charp tmp;
 
                tmp = text;
                text = (png_charp)png_malloc(png_ptr, text_size +
-                  (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
-                   + 1));
+                  (png_uint_32)(png_ptr->zbuf_size 
+                  - png_ptr->zstream.avail_out + 1));
                png_memcpy(text, tmp, text_size);
                png_free(png_ptr, tmp);
                png_memcpy(text + text_size, png_ptr->zbuf,
                   png_ptr->zbuf_size - png_ptr->zstream.avail_out);
                text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
                *(text + text_size) = '\0';
             }
             if (ret != Z_STREAM_END)
             {
                png_ptr->zstream.next_out = png_ptr->zbuf;
@@ skipping 62 matching lines @@
 
    if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
    {
       png_warning(png_ptr, "iTXt chunk too large to fit in memory");
       png_ptr->skip_length = length - (png_uint_32)65535L;
       length = (png_uint_32)65535L;
    }
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-         (png_uint_32)(length+1));
+      (png_uint_32)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
    png_ptr->current_text_left = (png_size_t)length;
    png_ptr->process_mode = PNG_READ_iTXt_MODE;
 }
 
 void /* PRIVATE */
 png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
 {
@@ skipping 80 matching lines @@
 #endif
 
 /* This function is called when we haven't found a handler for this
  * chunk.  If there isn't a problem with the chunk itself (ie a bad chunk
  * name or a critical chunk), the chunk is (currently) silently ignored.
  */
 void /* PRIVATE */
 png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
    length)
 {
-   png_uint_32 skip=0;
-   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+   png_uint_32 skip = 0;
 
    if (!(png_ptr->chunk_name[0] & 0x20))
    {
 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
-     if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
-          PNG_HANDLE_CHUNK_ALWAYS
+      if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+         PNG_HANDLE_CHUNK_ALWAYS
 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
-          && png_ptr->read_user_chunk_fn == NULL
+         && png_ptr->read_user_chunk_fn == NULL
 #endif
-        )
+         )
 #endif
-        png_chunk_error(png_ptr, "unknown critical chunk");
+         png_chunk_error(png_ptr, "unknown critical chunk");
 
-     info_ptr = info_ptr; /* to quiet some compiler warnings */
+      info_ptr = info_ptr; /* to quiet some compiler warnings */
    }
 
 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
    if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
    {
 #ifdef PNG_MAX_MALLOC_64K
       if (length > (png_uint_32)65535L)
       {
           png_warning(png_ptr, "unknown chunk too large to fit in memory");
           skip = length - (png_uint_32)65535L;
           length = (png_uint_32)65535L;
       }
 #endif
       png_memcpy((png_charp)png_ptr->unknown_chunk.name,
                  (png_charp)png_ptr->chunk_name, 
                  png_sizeof(png_ptr->unknown_chunk.name));
-      png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]='\0';
+      png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
+        = '\0';
 
       png_ptr->unknown_chunk.size = (png_size_t)length;
       if (length == 0)
          png_ptr->unknown_chunk.data = NULL;
       else
       {
-         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
+       (png_uint_32)length);
          png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
       }
 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
-      if(png_ptr->read_user_chunk_fn != NULL)
+      if (png_ptr->read_user_chunk_fn != NULL)
       {
          /* callback to user unknown chunk handler */
          int ret;
          ret = (*(png_ptr->read_user_chunk_fn))
            (png_ptr, &png_ptr->unknown_chunk);
          if (ret < 0)
             png_chunk_error(png_ptr, "error in user chunk");
          if (ret == 0)
          {
             if (!(png_ptr->chunk_name[0] & 0x20))
-               if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+               if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
                     PNG_HANDLE_CHUNK_ALWAYS)
                   png_chunk_error(png_ptr, "unknown critical chunk");
             png_set_unknown_chunks(png_ptr, info_ptr,
                &png_ptr->unknown_chunk, 1);
          }
       }
       else
 #endif
         png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
       png_free(png_ptr, png_ptr->unknown_chunk.data);
@@ skipping 28 matching lines @@
 }
 
 void PNGAPI
 png_progressive_combine_row (png_structp png_ptr,
    png_bytep old_row, png_bytep new_row)
 {
 #ifdef PNG_USE_LOCAL_ARRAYS
    PNG_CONST int FARDATA png_pass_dsp_mask[7] =
       {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
 #endif
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (new_row != NULL)    /* new_row must == png_ptr->row_buf here. */
       png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
 }
 
 void PNGAPI
 png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
    png_progressive_end_ptr end_fn)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->info_fn = info_fn;
    png_ptr->row_fn = row_fn;
    png_ptr->end_fn = end_fn;
 
    png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
 }
 
 png_voidp PNGAPI
 png_get_progressive_ptr(png_structp png_ptr)
 {
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
    return png_ptr->io_ptr;
 }
 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */