libpng: update to 1.2.43

third_party/libpng/png.c

 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.2.37 [June 4, 2009]
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2009 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.43 [February 25, 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.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
  */
 
 #define PNG_INTERNAL
 #define PNG_NO_EXTERN
+#define PNG_NO_PEDANTIC_WARNINGS
 #include "png.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_2_37 Your_png_h_is_not_version_1_2_37;
+typedef version_1_2_43 Your_png_h_is_not_version_1_2_43;
 
 /* Version information for C files.  This had better match the version
- * string defined in png.h.  */
+ * 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};
@@ skipping 36 matching lines @@
 
 /* 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};
+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 */
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
  * stream we can set num_bytes = 8 so that libpng will not attempt to read
  * or write any of the magic bytes before it starts on the IHDR.
  */
 
 #ifdef PNG_READ_SUPPORTED
 void PNGAPI
 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_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
 }
 
 /* Checks whether the supplied bytes match the PNG signature.  We allow
  * checking less than the full 8-byte signature so that those apps that
  * already read the first few bytes of a file to determine the file type
  * can simply check the remaining bytes for extra assurance.  Returns
@@ skipping 30 matching lines @@
   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 */
+voidpf /* PRIVATE */
 #endif
 png_zalloc(voidpf png_ptr, uInt items, uInt size)
 {
    png_voidp ptr;
    png_structp p=(png_structp)png_ptr;
    png_uint_32 save_flags=p->flags;
    png_uint_32 num_bytes;
 
    if (png_ptr == NULL)
       return (NULL);
@@ skipping 23 matching lines @@
       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 */
+void /* PRIVATE */
 #endif
 png_zfree(voidpf png_ptr, voidpf ptr)
 {
    png_free((png_structp)png_ptr, (png_voidp)ptr);
 }
 
 /* Reset the CRC variable to 32 bits of 1's.  Care must be taken
  * in case CRC is > 32 bits to leave the top bits 0.
  */
 void /* PRIVATE */
@@ skipping 33 matching lines @@
  * future.  This should be used in favour of malloc(png_sizeof(png_info))
  * and png_info_init() so that applications that want to use a shared
  * libpng don't have to be recompiled if png_info changes size.
  */
 png_infop PNGAPI
 png_create_info_struct(png_structp png_ptr)
 {
    png_infop info_ptr;
 
    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,
       png_ptr->malloc_fn, png_ptr->mem_ptr);
 #else
    info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
 #endif
    if (info_ptr != NULL)
       png_info_init_3(&info_ptr, png_sizeof(png_info));
 
    return (info_ptr);
 }
 
 /* This function frees the memory associated with a single info struct.
  * Normally, one would use either png_destroy_read_struct() or
  * png_destroy_write_struct() to free an info struct, but this may be
  * useful for some applications.
  */
 void PNGAPI
 png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
 {
    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;
 
    if (info_ptr != NULL)
    {
       png_info_destroy(png_ptr, info_ptr);
 
 #ifdef PNG_USER_MEM_SUPPORTED
       png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
           png_ptr->mem_ptr);
@@ skipping 16 matching lines @@
    /* We only come here via pre-1.0.12-compiled applications */
    png_info_init_3(&info_ptr, 0);
 }
 #endif
 
 void PNGAPI
 png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
 {
    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)
    {
       png_destroy_struct(info_ptr);
       info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
       *ptr_ptr = info_ptr;
    }
 
    /* Set everything to 0 */
    png_memset(info_ptr, 0, png_sizeof(png_info));
 }
 
 #ifdef PNG_FREE_ME_SUPPORTED
 void PNGAPI
 png_data_freer(png_structp png_ptr, png_infop info_ptr,
    int freer, png_uint_32 mask)
 {
    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;
    else if (freer == PNG_USER_WILL_FREE_DATA)
       info_ptr->free_me &= ~mask;
    else
       png_warning(png_ptr,
          "Unknown freer parameter in png_data_freer.");
 }
 #endif
 
 void PNGAPI
 png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
    int num)
 {
    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)
       {
          if (info_ptr->text && info_ptr->text[num].key)
          {
             png_free(png_ptr, info_ptr->text[num].key);
             info_ptr->text[num].key = NULL;
          }
       }
       else
       {
          int i;
          for (i = 0; i < info_ptr->num_text; i++)
              png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
          png_free(png_ptr, info_ptr->text);
          info_ptr->text = NULL;
          info_ptr->num_text=0;
       }
    }
 #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;
       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)
+#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)
       png_free(png_ptr, info_ptr->scal_s_width);
       png_free(png_ptr, info_ptr->scal_s_height);
       info_ptr->scal_s_width = NULL;
       info_ptr->scal_s_height = NULL;
 #endif
       info_ptr->valid &= ~PNG_INFO_sCAL;
    }
 #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);
       png_free(png_ptr, info_ptr->pcal_units);
       info_ptr->pcal_purpose = NULL;
       info_ptr->pcal_units = NULL;
       if (info_ptr->pcal_params != NULL)
          {
             int i;
             for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
             {
                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);
             info_ptr->pcal_params = NULL;
          }
       info_ptr->valid &= ~PNG_INFO_pCAL;
    }
 #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);
       png_free(png_ptr, info_ptr->iccp_profile);
       info_ptr->iccp_name = NULL;
       info_ptr->iccp_profile = NULL;
       info_ptr->valid &= ~PNG_INFO_iCCP;
    }
 #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)
       {
          if (info_ptr->splt_palettes)
@@ skipping 14 matching lines @@
 
             png_free(png_ptr, info_ptr->splt_palettes);
             info_ptr->splt_palettes = NULL;
             info_ptr->splt_palettes_num = 0;
          }
          info_ptr->valid &= ~PNG_INFO_sPLT;
       }
    }
 #endif
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
    if (png_ptr->unknown_chunk.data)
    {
       png_free(png_ptr, png_ptr->unknown_chunk.data);
       png_ptr->unknown_chunk.data = NULL;
    }
 
 #ifdef PNG_FREE_ME_SUPPORTED
    if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
 #else
    if (mask & PNG_FREE_UNKN)
@@ skipping 17 matching lines @@
                png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
 
             png_free(png_ptr, info_ptr->unknown_chunks);
             info_ptr->unknown_chunks = NULL;
             info_ptr->unknown_chunks_num = 0;
          }
       }
    }
 #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;
@@ skipping 12 matching lines @@
    {
       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)
       {
          int row;
          for (row = 0; row < (int)info_ptr->height; row++)
          {
             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;
    }
 #endif
 
 #ifdef PNG_FREE_ME_SUPPORTED
    if (num == -1)
       info_ptr->free_me &= ~mask;
    else
       info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
 #endif
 }
 
 /* This is an internal routine to free any memory that the info struct is
  * pointing to before re-using it or freeing the struct itself.  Recall
  * that png_free() checks for NULL pointers for us.
  */
 void /* PRIVATE */
 png_info_destroy(png_structp png_ptr, png_infop info_ptr)
 {
    png_debug(1, "in png_info_destroy");
 
    png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
 
-#if defined(PNG_UNKNOWN_CHUNKS_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;
    }
 #endif
 
    png_info_init_3(&info_ptr, png_sizeof(png_info));
 }
 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 
 /* This function returns a pointer to the io_ptr associated with the user
  * functions.  The application should free any memory associated with this
  * pointer before png_write_destroy() or png_read_destroy() are called.
  */
 png_voidp PNGAPI
 png_get_io_ptr(png_structp png_ptr)
 {
    if (png_ptr == NULL)
       return (NULL);
    return (png_ptr->io_ptr);
 }
 
 #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()
  * or png_set_write_fn() instead of png_init_io().  If you have defined
  * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
  * necessarily available.
  */
 void PNGAPI
 png_init_io(png_structp png_ptr, png_FILE_p fp)
 {
    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.
  */
 png_charp PNGAPI
 png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
 {
    static PNG_CONST char short_months[12][4] =
         {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
          "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
 
    if (png_ptr == NULL)
       return (NULL);
    if (png_ptr->time_buffer == NULL)
    {
       png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
          png_sizeof(char)));
    }
 
-#if defined(_WIN32_WCE)
+#ifdef _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);
+      WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer,
+          29, NULL, NULL);
    }
 #else
 #ifdef USE_FAR_KEYWORD
    {
       char near_time_buf[29];
       png_snprintf6(near_time_buf, 29, "%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);
       png_memcpy(png_ptr->time_buffer, near_time_buf,
           29*png_sizeof(char));
    }
 #else
    png_snprintf6(png_ptr->time_buffer, 29, "%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);
 #endif
 #endif /* _WIN32_WCE */
    return ((png_charp)png_ptr->time_buffer);
 }
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
 
 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 
 png_charp PNGAPI
 png_get_copyright(png_structp png_ptr)
 {
    png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
-   return ((png_charp) "\n libpng version 1.2.37 - June 4, 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 1.2.43 - February 25, 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 1.2.43 - February 25, 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
 }
 
 /* The following return the library version as a short string in the
  * format 1.0.0 through 99.99.99zz.  To get the version of *.h files
  * used with your application, print out PNG_LIBPNG_VER_STRING, which
  * is defined in png.h.
  * Note: now there is no difference between png_get_libpng_ver() and
  * png_get_header_ver().  Due to the version_nn_nn_nn typedef guard,
  * it is guaranteed that png.c uses the correct version of png.h.
  */
@@ skipping 11 matching lines @@
    /* Version of *.h files used when building libpng */
    png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_LIBPNG_VER_STRING);
 }
 
 png_charp PNGAPI
 png_get_header_version(png_structp png_ptr)
 {
    /* 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
 }
 
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 int PNGAPI
 png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
 {
    /* Check chunk_name and return "keep" value if it's on the list, else 0 */
    int i;
    png_bytep p;
@@ skipping 20 matching lines @@
 /* This function was added to libpng-1.0.7 */
 png_uint_32 PNGAPI
 png_access_version_number(void)
 {
    /* Version of *.c files used when building libpng */
    return((png_uint_32) PNG_LIBPNG_VER);
 }
 
 
 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
-#if !defined(PNG_1_0_X)
+#ifndef 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)
 #ifdef PNG_SIZE_T
 /* Added at libpng version 1.2.6 */
    PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
 png_size_t PNGAPI
 png_convert_size(size_t size)
 {
    if (size > (png_size_t)-1)
       PNG_ABORT();  /* We haven't got access to png_ptr, so no png_error() */
    return ((png_size_t)size);
 }
 #endif /* PNG_SIZE_T */
 
 /* 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
 
 /*
  *    Multiply two 32-bit numbers, V1 and V2, using 32-bit
  *    arithmetic, to produce a 64 bit result in the HI/LO words.
  *
  *                  A B
  *                x C D
  *               ------
  *              AD || BD
  *        AC || CB || 0
  *
  *    where A and B are the high and low 16-bit words of V1,
  *    C and D are the 16-bit words of V2, AD is the product of
  *    A and D, and X || Y is (X << 16) + Y.
 */
 
-void png_64bit_product (long v1, long v2, unsigned long *hi_product,
+void /* PRIVATE */
+png_64bit_product (long v1, long v2, unsigned long *hi_product,
    unsigned long *lo_product)
 {
    int a, b, c, d;
    long lo, hi, x, y;
 
    a = (v1 >> 16) & 0xffff;
    b = v1 & 0xffff;
    c = (v2 >> 16) & 0xffff;
    d = v2 & 0xffff;
 
    lo = b * d;                   /* BD */
    x = a * d + c * b;            /* AD + CB */
    y = ((lo >> 16) & 0xffff) + x;
 
    lo = (lo & 0xffff) | ((y & 0xffff) << 16);
    hi = (y >> 16) & 0xffff;
 
    hi += a * c;                  /* AC */
 
    *hi_product = (unsigned long)hi;
    *lo_product = (unsigned long)lo;
 }
 
-int /* private */
+int /* PRIVATE */
 png_check_cHRM_fixed(png_structp png_ptr,
    png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
    png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
    png_fixed_point blue_x, png_fixed_point blue_y)
 {
    int ret = 1;
    unsigned long xy_hi,xy_lo,yx_hi,yx_lo;
 
    png_debug(1, "in function png_check_cHRM_fixed");
+
    if (png_ptr == NULL)
       return 0;
 
    if (white_x < 0 || white_y <= 0 ||
          red_x < 0 ||   red_y <  0 ||
        green_x < 0 || green_y <  0 ||
         blue_x < 0 ||  blue_y <  0)
    {
       png_warning(png_ptr,
         "Ignoring attempt to set negative chromaticity value");
@@ skipping 38 matching lines @@
 
    if (xy_hi == yx_hi && xy_lo == yx_lo)
    {
       png_warning(png_ptr,
          "Ignoring attempt to set cHRM RGB triangle with zero area");
       ret = 0;
    }
 
    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) */