Changeset 846 for trunk/src/3rdparty/libpng/png.c

Timestamp:

May 5, 2011, 5:36:53 AM (14 years ago)

Author:

Dmitry A. Kuminov

Message:

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.

Location:

trunk

Files:

• . (modified) (1 prop)
• src/3rdparty/libpng/png.c (modified) (36 diffs)

trunk/src/3rdparty/libpng/png.c

@@ -2 +2 @@
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.2.39 [August 13, 2009]
- * Copyright (c) 1998-2009 Glenn Randers-Pehrson
+ * Last changed in libpng 1.4.0 [January 3, 2010]
+ * Copyright (c) 1998-2010 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.)
@@ -12 +12 @@
  */
 
-#define PNG_INTERNAL
 #define PNG_NO_EXTERN
+#define PNG_NO_PEDANTIC_WARNINGS
 #include "png.h"
+#include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_2_40 Your_png_h_is_not_version_1_2_40;
+typedef version_1_4_0 Your_png_h_is_not_version_1_4_0;
 
 /* Version information for C files.  This had better match the version
- * string defined in png.h.  */
-
-#ifdef PNG_USE_GLOBAL_ARRAYS
-/* png_libpng_ver was changed to a function in version 1.0.5c */
-PNG_CONST char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
-
-#ifdef PNG_READ_SUPPORTED
-
-/* png_sig was changed to a function in version 1.0.5c */
-/* Place to hold the signature string for a PNG file. */
-PNG_CONST png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
-#endif /* PNG_READ_SUPPORTED */
-
-/* Invoke global declarations for constant strings for known chunk types */
-PNG_IHDR;
-PNG_IDAT;
-PNG_IEND;
-PNG_PLTE;
-PNG_bKGD;
-PNG_cHRM;
-PNG_gAMA;
-PNG_hIST;
-PNG_iCCP;
-PNG_iTXt;
-PNG_oFFs;
-PNG_pCAL;
-PNG_sCAL;
-PNG_pHYs;
-PNG_sBIT;
-PNG_sPLT;
-PNG_sRGB;
-PNG_tEXt;
-PNG_tIME;
-PNG_tRNS;
-PNG_zTXt;
-
-#ifdef PNG_READ_SUPPORTED
-/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
-
-/* Start of interlace block */
-PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
-
-/* Offset to next interlace block */
-PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
-
-/* Start of interlace block in the y direction */
-PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
-
-/* Offset to next interlace block in the y direction */
-PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
-
-/* Height of interlace block.  This is not currently used - if you need
- * it, uncomment it here and in png.h
-PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
-*/
-
-/* Mask to determine which pixels are valid in a pass */
-PNG_CONST int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
-
-/* Mask to determine which pixels to overwrite while displaying */
-PNG_CONST int FARDATA png_pass_dsp_mask[]
-   = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
-
-#endif /* PNG_READ_SUPPORTED */
-#endif /* PNG_USE_GLOBAL_ARRAYS */
+ * string defined in png.h.
+ */
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
@@ -96 +34 @@
 png_set_sig_bytes(png_structp png_ptr, int num_bytes)
 {
+   png_debug(1, "in png_set_sig_bytes");
+
    if (png_ptr == NULL)
       return;
-   png_debug(1, "in png_set_sig_bytes");
+
    if (num_bytes > 8)
-      png_error(png_ptr, "Too many bytes for PNG signature.");
+      png_error(png_ptr, "Too many bytes for PNG signature");
 
    png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
@@ -131 +71 @@
 }
 
-#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
-/* (Obsolete) function to check signature bytes.  It does not allow one
- * to check a partial signature.  This function might be removed in the
- * future - use png_sig_cmp().  Returns true (nonzero) if the file is PNG.
- */
-int PNGAPI
-png_check_sig(png_bytep sig, int num)
-{
-  return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
-}
-#endif
 #endif /* PNG_READ_SUPPORTED */
 
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 /* Function to allocate memory for zlib and clear it to 0. */
-#ifdef PNG_1_0_X
-voidpf PNGAPI
-#else
 voidpf /* PRIVATE */
-#endif
 png_zalloc(voidpf png_ptr, uInt items, uInt size)
 {
@@ -156 +81 @@
    png_structp p=(png_structp)png_ptr;
    png_uint_32 save_flags=p->flags;
-   png_uint_32 num_bytes;
+   png_alloc_size_t num_bytes;
 
    if (png_ptr == NULL)
@@ -165 +90 @@
      return (NULL);
    }
-   num_bytes = (png_uint_32)items * size;
+   num_bytes = (png_alloc_size_t)items * size;
 
    p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
@@ -171 +96 @@
    p->flags=save_flags;
 
-#if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
-   if (ptr == NULL)
-       return ((voidpf)ptr);
-
-   if (num_bytes > (png_uint_32)0x8000L)
-   {
-      png_memset(ptr, 0, (png_size_t)0x8000L);
-      png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
-         (png_size_t)(num_bytes - (png_uint_32)0x8000L));
-   }
-   else
-   {
-      png_memset(ptr, 0, (png_size_t)num_bytes);
-   }
-#endif
    return ((voidpf)ptr);
 }
 
 /* Function to free memory for zlib */
-#ifdef PNG_1_0_X
-void PNGAPI
-#else
 void /* PRIVATE */
-#endif
 png_zfree(voidpf png_ptr, voidpf ptr)
 {
@@ -247 +153 @@
 
    png_debug(1, "in png_create_info_struct");
+
    if (png_ptr == NULL)
       return (NULL);
+
 #ifdef PNG_USER_MEM_SUPPORTED
    info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
@@ -270 +178 @@
 {
    png_infop info_ptr = NULL;
+
+   png_debug(1, "in png_destroy_info_struct");
+
    if (png_ptr == NULL)
       return;
 
-   png_debug(1, "in png_destroy_info_struct");
    if (info_ptr_ptr != NULL)
       info_ptr = *info_ptr_ptr;
@@ -295 +205 @@
  * instead.
  */
-#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
-#undef png_info_init
-void PNGAPI
-png_info_init(png_infop info_ptr)
-{
-   /* We only come here via pre-1.0.12-compiled applications */
-   png_info_init_3(&info_ptr, 0);
-}
-#endif
 
 void PNGAPI
@@ -310 +211 @@
    png_infop info_ptr = *ptr_ptr;
 
+   png_debug(1, "in png_info_init_3");
+
    if (info_ptr == NULL)
       return;
-
-   png_debug(1, "in png_info_init_3");
 
    if (png_sizeof(png_info) > png_info_struct_size)
@@ -326 +227 @@
 }
 
-#ifdef PNG_FREE_ME_SUPPORTED
 void PNGAPI
 png_data_freer(png_structp png_ptr, png_infop info_ptr,
@@ -332 +232 @@
 {
    png_debug(1, "in png_data_freer");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
+
    if (freer == PNG_DESTROY_WILL_FREE_DATA)
       info_ptr->free_me |= mask;
@@ -340 +242 @@
    else
       png_warning(png_ptr,
-         "Unknown freer parameter in png_data_freer.");
-}
-#endif
+         "Unknown freer parameter in png_data_freer");
+}
 
 void PNGAPI
@@ -349 +250 @@
 {
    png_debug(1, "in png_free_data");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-#if defined(PNG_TEXT_SUPPORTED)
+#ifdef PNG_TEXT_SUPPORTED
    /* Free text item num or (if num == -1) all text items */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
-#else
-   if (mask & PNG_FREE_TEXT)
-#endif
    {
       if (num != -1)
@@ -380 +278 @@
 #endif
 
-#if defined(PNG_tRNS_SUPPORTED)
+#ifdef PNG_tRNS_SUPPORTED
    /* Free any tRNS entry */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
-#else
-   if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
-#endif
-   {
-      png_free(png_ptr, info_ptr->trans);
-      info_ptr->trans = NULL;
+   {
+      png_free(png_ptr, info_ptr->trans_alpha);
+      info_ptr->trans_alpha = NULL;
       info_ptr->valid &= ~PNG_INFO_tRNS;
-#ifndef PNG_FREE_ME_SUPPORTED
-      png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
-#endif
-   }
-#endif
-
-#if defined(PNG_sCAL_SUPPORTED)
+   }
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
    /* Free any sCAL entry */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
-#else
-   if (mask & PNG_FREE_SCAL)
-#endif
    {
 #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
@@ -415 +302 @@
 #endif
 
-#if defined(PNG_pCAL_SUPPORTED)
+#ifdef PNG_pCAL_SUPPORTED
    /* Free any pCAL entry */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
-#else
-   if (mask & PNG_FREE_PCAL)
-#endif
    {
       png_free(png_ptr, info_ptr->pcal_purpose);
@@ -433 +316 @@
             {
                png_free(png_ptr, info_ptr->pcal_params[i]);
-               info_ptr->pcal_params[i]=NULL;
+               info_ptr->pcal_params[i] = NULL;
             }
             png_free(png_ptr, info_ptr->pcal_params);
@@ -442 +325 @@
 #endif
 
-#if defined(PNG_iCCP_SUPPORTED)
+#ifdef PNG_iCCP_SUPPORTED
    /* Free any iCCP entry */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
-#else
-   if (mask & PNG_FREE_ICCP)
-#endif
    {
       png_free(png_ptr, info_ptr->iccp_name);
@@ -458 +337 @@
 #endif
 
-#if defined(PNG_sPLT_SUPPORTED)
+#ifdef PNG_sPLT_SUPPORTED
    /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
-#else
-   if (mask & PNG_FREE_SPLT)
-#endif
    {
       if (num != -1)
@@ -493 +368 @@
 #endif
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
    if (png_ptr->unknown_chunk.data)
    {
@@ -500 +375 @@
    }
 
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
-#else
-   if (mask & PNG_FREE_UNKN)
-#endif
    {
       if (num != -1)
@@ -531 +402 @@
 #endif
 
-#if defined(PNG_hIST_SUPPORTED)
+#ifdef PNG_hIST_SUPPORTED
    /* Free any hIST entry */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_HIST)  & info_ptr->free_me)
-#else
-   if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
-#endif
    {
       png_free(png_ptr, info_ptr->hist);
       info_ptr->hist = NULL;
       info_ptr->valid &= ~PNG_INFO_hIST;
-#ifndef PNG_FREE_ME_SUPPORTED
-      png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
-#endif
    }
 #endif
 
    /* Free any PLTE entry that was internally allocated */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
-#else
-   if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
-#endif
    {
       png_zfree(png_ptr, info_ptr->palette);
       info_ptr->palette = NULL;
       info_ptr->valid &= ~PNG_INFO_PLTE;
-#ifndef PNG_FREE_ME_SUPPORTED
-      png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
-#endif
       info_ptr->num_palette = 0;
    }
 
-#if defined(PNG_INFO_IMAGE_SUPPORTED)
+#ifdef PNG_INFO_IMAGE_SUPPORTED
    /* Free any image bits attached to the info structure */
-#ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
-#else
-   if (mask & PNG_FREE_ROWS)
-#endif
    {
       if (info_ptr->row_pointers)
@@ -578 +431 @@
          {
             png_free(png_ptr, info_ptr->row_pointers[row]);
-            info_ptr->row_pointers[row]=NULL;
+            info_ptr->row_pointers[row] = NULL;
          }
          png_free(png_ptr, info_ptr->row_pointers);
-         info_ptr->row_pointers=NULL;
+         info_ptr->row_pointers = NULL;
       }
       info_ptr->valid &= ~PNG_INFO_IDAT;
@@ -587 +440 @@
 #endif
 
-#ifdef PNG_FREE_ME_SUPPORTED
    if (num == -1)
       info_ptr->free_me &= ~mask;
    else
       info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
-#endif
 }
 
@@ -606 +457 @@
    png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
 
-#if defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
    if (png_ptr->num_chunk_list)
    {
       png_free(png_ptr, png_ptr->chunk_list);
-      png_ptr->chunk_list=NULL;
+      png_ptr->chunk_list = NULL;
       png_ptr->num_chunk_list = 0;
    }
@@ -632 +483 @@
 
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-#if !defined(PNG_NO_STDIO)
+#ifdef PNG_STDIO_SUPPORTED
 /* Initialize the default input/output functions for the PNG file.  If you
  * use your own read or write routines, you can call either png_set_read_fn()
@@ -643 +494 @@
 {
    png_debug(1, "in png_init_io");
+
    if (png_ptr == NULL)
       return;
+
    png_ptr->io_ptr = (png_voidp)fp;
 }
 #endif
 
-#if defined(PNG_TIME_RFC1123_SUPPORTED)
+#ifdef PNG_TIME_RFC1123_SUPPORTED
 /* Convert the supplied time into an RFC 1123 string suitable for use in
  * a "Creation Time" or other text-based time string.
@@ -668 +521 @@
    }
 
-#if defined(_WIN32_WCE)
-   {
-      wchar_t time_buf[29];
-      wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
-          ptime->day % 32, short_months[(ptime->month - 1) % 12],
-        ptime->year, ptime->hour % 24, ptime->minute % 60,
-          ptime->second % 61);
-      WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
-          NULL, NULL);
-   }
-#else
 #ifdef USE_FAR_KEYWORD
    {
@@ -695 +537 @@
        ptime->second % 61);
 #endif
-#endif /* _WIN32_WCE */
    return ((png_charp)png_ptr->time_buffer);
 }
@@ -706 +547 @@
 {
    png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
-   return ((png_charp) "\n libpng version 1.2.40 - September 10, 2009\n\
-   Copyright (c) 1998-2009 Glenn Randers-Pehrson\n\
-   Copyright (c) 1996-1997 Andreas Dilger\n\
-   Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
+#ifdef PNG_STRING_COPYRIGHT
+      return PNG_STRING_COPYRIGHT
+#else
+#ifdef __STDC__
+   return ((png_charp) PNG_STRING_NEWLINE \
+     "libpng version 1.4.0 - January 3, 2010" PNG_STRING_NEWLINE \
+     "Copyright (c) 1998-2010 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
+     "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
+     "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
+     PNG_STRING_NEWLINE);
+#else
+      return ((png_charp) "libpng version 1.4.0 - January 3, 2010\
+      Copyright (c) 1998-2010 Glenn Randers-Pehrson\
+      Copyright (c) 1996-1997 Andreas Dilger\
+      Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
+#endif
+#endif
 }
 
@@ -741 +595 @@
    /* Returns longer string containing both version and date */
    png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+#ifdef __STDC__
    return ((png_charp) PNG_HEADER_VERSION_STRING
 #ifndef PNG_READ_SUPPORTED
    "     (NO READ SUPPORT)"
 #endif
-   "\n");
+   PNG_STRING_NEWLINE);
+#else
+   return ((png_charp) PNG_HEADER_VERSION_STRING);
+#endif
 }
 
@@ -785 +643 @@
 
 
-#if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
-#if !defined(PNG_1_0_X)
-/* This function was added to libpng 1.2.0 */
-int PNGAPI
-png_mmx_support(void)
-{
-   /* Obsolete, to be removed from libpng-1.4.0 */
-    return -1;
-}
-#endif /* PNG_1_0_X */
-#endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */
 
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
@@ -811 +658 @@
 
 /* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
-#if defined(PNG_cHRM_SUPPORTED)
-#if !defined(PNG_NO_CHECK_cHRM)
+#ifdef PNG_cHRM_SUPPORTED
+#ifdef PNG_CHECK_cHRM_SUPPORTED
 
 /*
@@ -864 +711 @@
 
    png_debug(1, "in function png_check_cHRM_fixed");
+
    if (png_ptr == NULL)
       return 0;
@@ -922 +770 @@
    return ret;
 }
-#endif /* NO_PNG_CHECK_cHRM */
+#endif /* PNG_CHECK_cHRM_SUPPORTED */
 #endif /* PNG_cHRM_SUPPORTED */
+
+void /* PRIVATE */
+png_check_IHDR(png_structp png_ptr,
+   png_uint_32 width, png_uint_32 height, int bit_depth,
+   int color_type, int interlace_type, int compression_type,
+   int filter_type)
+{
+   int error = 0;
+
+   /* Check for width and height valid values */
+   if (width == 0)
+   {
+      png_warning(png_ptr, "Image width is zero in IHDR");
+      error = 1;
+   }
+
+   if (height == 0)
+   {
+      png_warning(png_ptr, "Image height is zero in IHDR");
+      error = 1;
+   }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX)
+#else
+   if (width > PNG_USER_WIDTH_MAX)
+#endif
+   {
+      png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+      error = 1;
+   }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX)
+#else
+   if (height > PNG_USER_HEIGHT_MAX)
+#endif
+   {
+      png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+      error = 1;
+   }
+
+   if (width > PNG_UINT_31_MAX)
+   {
+      png_warning(png_ptr, "Invalid image width in IHDR");
+      error = 1;
+   }
+
+   if ( height > PNG_UINT_31_MAX)
+   {
+      png_warning(png_ptr, "Invalid image height in IHDR");
+      error = 1;
+   }
+
+   if ( width > (PNG_UINT_32_MAX
+                 >> 3)      /* 8-byte RGBA pixels */
+                 - 64       /* bigrowbuf hack */
+                 - 1        /* filter byte */
+                 - 7*8      /* rounding of width to multiple of 8 pixels */
+                 - 8)       /* extra max_pixel_depth pad */
+      png_warning(png_ptr, "Width is too large for libpng to process pixels");
+
+   /* Check other values */
+   if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+       bit_depth != 8 && bit_depth != 16)
+   {
+      png_warning(png_ptr, "Invalid bit depth in IHDR");
+      error = 1;
+   }
+
+   if (color_type < 0 || color_type == 1 ||
+       color_type == 5 || color_type > 6)
+   {
+      png_warning(png_ptr, "Invalid color type in IHDR");
+      error = 1;
+   }
+
+   if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+       ((color_type == PNG_COLOR_TYPE_RGB ||
+         color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+         color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+   {
+      png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
+      error = 1;
+   }
+
+   if (interlace_type >= PNG_INTERLACE_LAST)
+   {
+      png_warning(png_ptr, "Unknown interlace method in IHDR");
+      error = 1;
+   }
+
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Unknown compression method in IHDR");
+      error = 1;
+   }
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   /* Accept filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not read a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) &&
+       png_ptr->mng_features_permitted)
+      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+
+   if (filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+         (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+         ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+         (color_type == PNG_COLOR_TYPE_RGB ||
+         color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+      {
+         png_warning(png_ptr, "Unknown filter method in IHDR");
+         error = 1;
+      }
+
+      if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE)
+      {
+         png_warning(png_ptr, "Invalid filter method in IHDR");
+         error = 1;
+      }
+   }
+
+#else
+   if (filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Unknown filter method in IHDR");
+      error = 1;
+   }
+#endif
+
+   if (error == 1)
+      png_error(png_ptr, "Invalid IHDR data");
+}
 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */