[libpng12] Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from

pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
    now that png_ptr->buffer is inaccessible to applications, the special
    handling is no longer useful.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.2.48beta01 - February 20, 2012
+Libpng 1.2.48beta01 - February 22, 2012
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -42,8 +42,12 @@ Other information:
 
 Changes since the last public release (1.2.46):
 
-version 1.2.48beta01 [February 20, 2012]
+version 1.2.48beta01 [February 22, 2012]
   Removed two useless #ifdef directives from pngread.c and one from pngrutil.c
+  Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
+    pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
+    now that png_ptr->buffer is inaccessible to applications, the special
+    handling is no longer useful.
 
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CHANGES

@@ -2745,8 +2745,13 @@ version 1.0.57rc01 and 1.2.47rc01 [February 17, 2012]
 version 1.0.57 and 1.2.47 [February 18, 2012]
   No changes.
 
-version 1.2.48beta01 [February 20, 2012]
+version 1.2.48beta01 [February 22, 2012]
   Removed two useless #ifdef directives from pngread.c and one from pngrutil.c
+  Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
+    pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
+    now that png_ptr->buffer is inaccessible to applications, the special
+    handling is no longer useful.
+  Fixed bug with png_handle_hIST with odd chunk length (Frank Busse).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

pngpread.c

@@ -71,30 +71,6 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
          break;
       }
 
-#ifdef PNG_READ_tEXt_SUPPORTED
-      case PNG_READ_tEXt_MODE:
-      {
-         png_push_read_tEXt(png_ptr, info_ptr);
-         break;
-      }
-
-#endif
-#ifdef PNG_READ_zTXt_SUPPORTED
-      case PNG_READ_zTXt_MODE:
-      {
-         png_push_read_zTXt(png_ptr, info_ptr);
-         break;
-      }
-
-#endif
-#ifdef PNG_READ_iTXt_SUPPORTED
-      case PNG_READ_iTXt_MODE:
-      {
-         png_push_read_iTXt(png_ptr, info_ptr);
-         break;
-      }
-
-#endif
       case PNG_SKIP_MODE:
       {
          png_push_crc_finish(png_ptr);
@@ -529,7 +505,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
          return;
       }
 
-      png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
 #endif
@@ -542,7 +518,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
          return;
       }
 
-      png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
 #endif
@@ -555,7 +531,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
          return;
       }
 
-      png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
 #endif
@@ -566,7 +542,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
          png_push_save_buffer(png_ptr);
          return;
       }
-      png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
    }
 
    png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
@@ -1201,515 +1177,6 @@ png_read_push_finish_row(png_structp png_ptr)
 #endif /* PNG_READ_INTERLACING_SUPPORTED */
 }
 
-#ifdef 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_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)
-{
-   if (png_ptr->buffer_size && png_ptr->current_text_left)
-   {
-      png_size_t text_size;
-
-      if (png_ptr->buffer_size < png_ptr->current_text_left)
-         text_size = png_ptr->buffer_size;
-
-      else
-         text_size = png_ptr->current_text_left;
-
-      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
-      png_ptr->current_text_left -= text_size;
-      png_ptr->current_text_ptr += text_size;
-   }
-   if (!(png_ptr->current_text_left))
-   {
-      png_textp text_ptr;
-      png_charp text;
-      png_charp key;
-      int ret;
-
-      if (png_ptr->buffer_size < 4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
-      png_push_crc_finish(png_ptr);
-
-#ifdef PNG_MAX_MALLOC_64K
-      if (png_ptr->skip_length)
-         return;
-#endif
-
-      key = png_ptr->current_text;
-
-      for (text = key; *text; text++)
-         /* Empty loop */ ;
-
-      if (text < key + png_ptr->current_text_size)
-         text++;
-
-      text_ptr = (png_textp)png_malloc(png_ptr,
-         (png_uint_32)png_sizeof(png_text));
-      text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
-      text_ptr->key = key;
-#ifdef PNG_iTXt_SUPPORTED
-      text_ptr->lang = NULL;
-      text_ptr->lang_key = NULL;
-#endif
-      text_ptr->text = text;
-
-      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
-
-      png_free(png_ptr, key);
-      png_free(png_ptr, text_ptr);
-      png_ptr->current_text = NULL;
-
-      if (ret)
-        png_warning(png_ptr, "Insufficient memory to store text chunk.");
-   }
-}
-#endif
-
-#ifdef PNG_READ_zTXt_SUPPORTED
-void /* PRIVATE */
-png_push_handle_zTXt(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 zTXt");
-         info_ptr = info_ptr; /* To quiet some compiler warnings */
-      }
-
-#ifdef PNG_MAX_MALLOC_64K
-   /* We can't handle zTXt chunks > 64K, since we don't have enough space
-    * to be able to store the uncompressed data.  Actually, the threshold
-    * is probably around 32K, but it isn't as definite as 64K is.
-    */
-   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_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)
-{
-   if (png_ptr->buffer_size && png_ptr->current_text_left)
-   {
-      png_size_t text_size;
-
-      if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
-         text_size = png_ptr->buffer_size;
-
-      else
-         text_size = png_ptr->current_text_left;
-
-      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
-      png_ptr->current_text_left -= text_size;
-      png_ptr->current_text_ptr += text_size;
-   }
-   if (!(png_ptr->current_text_left))
-   {
-      png_textp text_ptr;
-      png_charp text;
-      png_charp key;
-      int ret;
-      png_size_t text_size, key_size;
-
-      if (png_ptr->buffer_size < 4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
-      png_push_crc_finish(png_ptr);
-
-      key = png_ptr->current_text;
-
-      for (text = key; *text; text++)
-         /* Empty loop */ ;
-
-      /* zTXt can't have zero text */
-      if (text >= key + png_ptr->current_text_size)
-      {
-         png_ptr->current_text = NULL;
-         png_free(png_ptr, key);
-         return;
-      }
-
-      text++;
-
-      if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
-      {
-         png_ptr->current_text = NULL;
-         png_free(png_ptr, key);
-         return;
-      }
-
-      text++;
-
-      png_ptr->zstream.next_in = (png_bytep )text;
-      png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
-         (text - key));
-      png_ptr->zstream.next_out = png_ptr->zbuf;
-      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-
-      key_size = text - key;
-      text_size = 0;
-      text = NULL;
-      ret = Z_STREAM_END;
-
-      while (png_ptr->zstream.avail_in)
-      {
-         ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
-         if (ret != Z_OK && ret != Z_STREAM_END)
-         {
-            inflateReset(&png_ptr->zstream);
-            png_ptr->zstream.avail_in = 0;
-            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_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_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;
-               png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-            }
-         }
-         else
-         {
-            break;
-         }
-
-         if (ret == Z_STREAM_END)
-            break;
-      }
-
-      inflateReset(&png_ptr->zstream);
-      png_ptr->zstream.avail_in = 0;
-
-      if (ret != Z_STREAM_END)
-      {
-         png_ptr->current_text = NULL;
-         png_free(png_ptr, key);
-         png_free(png_ptr, text);
-         return;
-      }
-
-      png_ptr->current_text = NULL;
-      png_free(png_ptr, key);
-      key = text;
-      text += key_size;
-
-      text_ptr = (png_textp)png_malloc(png_ptr,
-          (png_uint_32)png_sizeof(png_text));
-      text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
-      text_ptr->key = key;
-#ifdef PNG_iTXt_SUPPORTED
-      text_ptr->lang = NULL;
-      text_ptr->lang_key = NULL;
-#endif
-      text_ptr->text = text;
-
-      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
-
-      png_free(png_ptr, key);
-      png_free(png_ptr, text_ptr);
-
-      if (ret)
-        png_warning(png_ptr, "Insufficient memory to store text chunk.");
-   }
-}
-#endif
-
-#ifdef PNG_READ_iTXt_SUPPORTED
-void /* PRIVATE */
-png_push_handle_iTXt(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 iTXt");
-         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, "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_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)
-{
-
-   if (png_ptr->buffer_size && png_ptr->current_text_left)
-   {
-      png_size_t text_size;
-
-      if (png_ptr->buffer_size < png_ptr->current_text_left)
-         text_size = png_ptr->buffer_size;
-
-      else
-         text_size = png_ptr->current_text_left;
-
-      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
-      png_ptr->current_text_left -= text_size;
-      png_ptr->current_text_ptr += text_size;
-   }
-   if (!(png_ptr->current_text_left))
-   {
-      png_textp text_ptr;
-      png_charp key;
-      int comp_flag;
-      png_charp lang;
-      png_charp lang_key;
-      png_charp text;
-      int ret;
-
-      if (png_ptr->buffer_size < 4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
-      png_push_crc_finish(png_ptr);
-
-#ifdef PNG_MAX_MALLOC_64K
-      if (png_ptr->skip_length)
-         return;
-#endif
-
-      key = png_ptr->current_text;
-
-      for (lang = key; *lang; lang++)
-         /* Empty loop */ ;
-
-      if (lang < key + png_ptr->current_text_size - 3)
-         lang++;
-
-      comp_flag = *lang++;
-      lang++;     /* Skip comp_type, always zero */
-
-      for (lang_key = lang; *lang_key; lang_key++)
-         /* Empty loop */ ;
-
-      lang_key++;        /* Skip NUL separator */
-
-      text=lang_key;
-
-      if (lang_key < key + png_ptr->current_text_size - 1)
-      {
-        for (; *text; text++)
-           /* Empty loop */ ;
-      }
-
-      if (text < key + png_ptr->current_text_size)
-         text++;
-
-      text_ptr = (png_textp)png_malloc(png_ptr,
-         (png_uint_32)png_sizeof(png_text));
-
-      text_ptr->compression = comp_flag + 2;
-      text_ptr->key = key;
-      text_ptr->lang = lang;
-      text_ptr->lang_key = lang_key;
-      text_ptr->text = text;
-      text_ptr->text_length = 0;
-      text_ptr->itxt_length = png_strlen(text);
-
-      ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
-
-      png_ptr->current_text = NULL;
-
-      png_free(png_ptr, text_ptr);
-      if (ret)
-         png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
-   }
-}
-#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;
-
-   if (!(png_ptr->chunk_name[0] & 0x20))
-   {
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-      if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
-         PNG_HANDLE_CHUNK_ALWAYS
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
-         && png_ptr->read_user_chunk_fn == NULL
-#endif
-         )
-#endif
-         png_chunk_error(png_ptr, "unknown critical chunk");
-
-      info_ptr = info_ptr; /* To quiet some compiler warnings */
-   }
-
-#ifdef 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.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,
-            (png_uint_32)length);
-         png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
-      }
-
-#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
-      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) !=
-                    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);
-      png_ptr->unknown_chunk.data = NULL;
-   }
-
-   else
-#endif
-      skip=length;
-   png_push_crc_skip(png_ptr, skip);
-}
-
 void /* PRIVATE */
 png_push_have_info(png_structp png_ptr, png_infop info_ptr)
 {

pngrutil.c

@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.2.48 [February 20, 2012]
+ * Last changed in libpng 1.2.48 [February 22, 2012]
  * Copyright (c) 1998-2012 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.)
@@ -1530,15 +1530,16 @@ png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       return;
    }
 
-   num = length / 2 ;
+   if (length > 2*PNG_MAX_PALETTE_LENGTH ||
-   if (num != (unsigned int) png_ptr->num_palette || num >
+       length != (unsigned int) (2*png_ptr->num_palette))
-      (unsigned int) PNG_MAX_PALETTE_LENGTH)
    {
       png_warning(png_ptr, "Incorrect hIST chunk length");
       png_crc_finish(png_ptr, length);
       return;
    }
 
+   num = length / 2 ;
+
    for (i = 0; i < num; i++)
    {
       png_byte buf[2];