[libng16] Added palette-index checking while writing.

Relocated palette-index checking function from pngrutil.c to pngtrans.c

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.6.0beta16 - March 2, 2012
+Libpng 1.6.0beta16 - March 3, 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.
@@ -258,7 +258,9 @@ Version 1.6.0beta15 [March 2, 2012]
     without the necessary color data.
   Removed whitespace from the end of lines in all source files and scripts.
 
-Version 1.6.0beta16 [March 2, 2012]
+Version 1.6.0beta16 [March 3, 2012]
+  Relocated palette-index checking function from pngrutil.c to pngtrans.c
+  Added palette-index checking while writing.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4002,15 +4002,16 @@ Version 1.6.0beta15 [March 2, 2012]
     allow the error numbers in pngstest to be tuned and checked.  makepng
     also allows generation of images with extra chunks, although this is
     still work-in-progress.
-  Added tests for invalid palette index while reading and writing (work in
+  Added check for invalid palette index while reading.
-    progress, the latter isn't finished).
   Fixed some bugs in ICC profile writing. The code should now accept
     all potentially valid ICC profiles and reject obviously invalid ones.
     It now uses png_error() to do so rather than casually writing a PNG
     without the necessary color data.
   Removed whitespace from the end of lines in all source files and scripts.
 
-Version 1.6.0beta16 [March 2, 2012]
+Version 1.6.0beta16 [March 3, 2012]
+  Relocated palette-index checking function from pngrutil.c to pngtrans.c
+  Added palette-index checking while writing.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.0beta16 - March 2, 2012
+ * libpng version 1.6.0beta16 - March 3, 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.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.0beta16 - March 2, 2012: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.0beta16 - March 3, 2012: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -198,7 +198,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.0beta16, March 2, 2012, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.0beta16, March 3, 2012, are
  * Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -310,7 +310,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    March 2, 2012
+ *    March 3, 2012
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -376,7 +376,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.6.0beta16"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.0beta16 - March 2, 2012\n"
+     " libpng version 1.6.0beta16 - March 3, 2012\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -3066,6 +3066,12 @@ PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
  *  END OF SIMPLIFIED API
  ******************************************************************************/
 
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+PNG_EXPORT(242, void, png_set_check_for_invalid_index,
+    (png_structrp png_ptr, int allowed));
+#endif
+
 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project
  * defs
  */
@@ -3075,7 +3081,7 @@ PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
  * scripts/symbols.def as well.
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(241);
+  PNG_EXPORT_LAST_ORDINAL(242);
 #endif
 
 #ifdef __cplusplus

pngpriv.h

@@ -1438,6 +1438,13 @@ PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
     int color_type, int interlace_type, int compression_type,
     int filter_type),PNG_EMPTY);
 
+/* Added at libpng version 1.5.10 */
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
+   (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
+#endif
+
 #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
 PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
    png_const_charp name),PNG_NORETURN);

pngread.c

@@ -748,8 +748,7 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
    /* Report invalid palette index; added at libng-1.5.10 */
    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
       png_ptr->num_palette_max > png_ptr->num_palette)
-     png_warning(png_ptr, "palette index exceeded num_palette; "
+     png_warning(png_ptr, "Read palette index exceeding num_palette");
-         "pixel(s) rendered opaque black");
 #endif
 
    do

pngrtran.c

@@ -2296,101 +2296,8 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 
 #ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
    /* Added at libpng-1.5.10 */
-
    if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
-   {
+      png_do_check_palette_indexes(png_ptr, row_info);
-      if (png_ptr->num_palette < (1 << png_ptr->bit_depth) &&
-         ((png_ptr->interlaced && png_ptr->pass == 6) ||
-         (!png_ptr->interlaced && png_ptr->pass == 0)))
-      {
-         png_bytep rp = png_ptr->row_buf + 1 + row_info->rowbytes;
-
-         switch (row_info->bit_depth)
-         {
-            case 1:
-            {
-               /* in this case, all bytes must be 0 so we don't need
-                * to unpack the pixels except for the rightmost one.
-                */
-               int padding = 8*row_info->rowbytes - png_ptr->width;
-
-               for (; rp > png_ptr->row_buf; rp--)
-               {
-                 if (*rp >> padding != 0)
-                    png_ptr->num_palette_max = 1;
-                 padding = 0;
-               }
-
-               break;
-            }
-
-            case 2:
-            {
-               int padding = 2*(4*row_info->rowbytes - png_ptr->width);
-
-               for (; rp > png_ptr->row_buf; rp--)
-               {
-                 int index = ((*rp >> padding) & 0x03);
-
-                 if (index > png_ptr->num_palette_max)
-                    png_ptr->num_palette_max = index;
-
-                 index = (((*rp >> padding) >> 2) & 0x03);
-
-                 if (index > png_ptr->num_palette_max)
-                    png_ptr->num_palette_max = index;
-
-                 index = (((*rp >> padding) >> 4) & 0x03);
-
-                 if (index > png_ptr->num_palette_max)
-                    png_ptr->num_palette_max = index;
-
-                 index = (((*rp >> padding) >> 6) & 0x03);
-
-                 if (index > png_ptr->num_palette_max)
-                    png_ptr->num_palette_max = index;
-
-                 padding = 0;
-               }
-
-               break;
-            }
-
-            case 4:
-            {
-               int padding = 4*(2*row_info->rowbytes - png_ptr->width);
-
-               for (; rp > png_ptr->row_buf; rp--)
-               {
-                 int index = ((*rp >> padding) & 0x0f);
-
-                 if (index > png_ptr->num_palette_max)
-                    png_ptr->num_palette_max = index;
-
-                 index = (((*rp >> padding) >> 4) & 0x0f);
-
-                 if (index > png_ptr->num_palette_max)
-                    png_ptr->num_palette_max = index;
-
-                 padding = 0;
-               }
-
-               break;
-            }
-
-            case 8:
-            {
-               for (; rp > png_ptr->row_buf; rp--)
-               {
-                  if (*rp >= png_ptr->num_palette_max)
-                     png_ptr->num_palette_max = *rp;
-               }
-
-               break;
-            }
-         }
-      }
-   }
 #endif
 
 #ifdef PNG_READ_BGR_SUPPORTED

pngset.c

@@ -1310,4 +1310,22 @@ png_set_benign_errors(png_structrp png_ptr, int allowed)
       png_ptr->flags &= ~PNG_FLAG_BENIGN_ERRORS_WARN;
 }
 #endif /* PNG_BENIGN_ERRORS_SUPPORTED */
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   /* Do not report invalid palette index; added at libng-1.5.10 */
+void PNGAPI
+png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
+{
+   png_debug(1, "in png_set_check_for_invalid_index");
+
+   if (allowed)
+      png_ptr->num_palette_max = 0;
+
+   else
+      png_ptr->num_palette_max = -1;
+}
+
+
+#endif
+
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pngstruct.h

@@ -126,7 +126,7 @@ struct png_struct_def
 
 /* Added at libpng-1.5.10 */
 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
-   png_uint_16 num_palette_max; /* maximum palette index found in IDAT */
+   int num_palette_max;       /* maximum palette index found in IDAT */
 #endif
 
    png_uint_16 num_trans;     /* number of transparency values */

pngtrans.c

@@ -619,6 +619,107 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
 }
 #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
 
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+/* Added at libpng-1.5.10 */
+void /* PRIVATE */
+png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
+{
+      if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
+         png_ptr->num_palette_max >= 0 &&
+         ((png_ptr->interlaced && png_ptr->pass == 6) ||
+         (!png_ptr->interlaced && png_ptr->pass == 0)))
+   {
+      png_bytep rp = png_ptr->row_buf + 1 + row_info->rowbytes;
+
+      switch (row_info->bit_depth)
+      {
+         case 1:
+         {
+            /* in this case, all bytes must be 0 so we don't need
+             * to unpack the pixels except for the rightmost one.
+             */
+            int padding = 8*row_info->rowbytes - png_ptr->width;
+
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              if (*rp >> padding != 0)
+                 png_ptr->num_palette_max = 1;
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 2:
+         {
+            int padding = 2*(4*row_info->rowbytes - png_ptr->width);
+
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              int index = ((*rp >> padding) & 0x03);
+
+              if (index > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = index;
+
+              index = (((*rp >> padding) >> 2) & 0x03);
+
+              if (index > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = index;
+
+              index = (((*rp >> padding) >> 4) & 0x03);
+
+              if (index > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = index;
+
+              index = (((*rp >> padding) >> 6) & 0x03);
+
+              if (index > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = index;
+
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 4:
+         {
+            int padding = 4*(2*row_info->rowbytes - png_ptr->width);
+
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              int index = ((*rp >> padding) & 0x0f);
+
+              if (index > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = index;
+
+              index = (((*rp >> padding) >> 4) & 0x0f);
+
+              if (index > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = index;
+
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 8:
+         {
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+               if (*rp >= png_ptr->num_palette_max)
+                  png_ptr->num_palette_max = (int) *rp;
+            }
+
+            break;
+         }
+      }
+   }
+}
+#endif /* PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED */
+
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

pngwrite.c

@@ -308,6 +308,11 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
    if (!(png_ptr->mode & PNG_HAVE_IDAT))
       png_error(png_ptr, "No IDATs written into file");
 
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   if (png_ptr->num_palette_max > png_ptr->num_palette)
+      png_warning(png_ptr, "Wrote palette index exceeding num_palette");
+#endif
+
    /* See if user wants us to write information chunks */
    if (info_ptr != NULL)
    {
@@ -734,13 +739,8 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
 /* Added at libpng-1.5.10 */
 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
    /* Check for out-of-range palette index */
-#if 0 /* To do: implement png_do_check_palette_indexes() */
+   if(row_info.color_type == PNG_COLOR_TYPE_PALETTE)
-   if (png_ptr->num_palette < (1 << png_ptr->bit_depth))
+      png_do_check_palette_indexes(png_ptr, &row_info);
-      png_do_check_palette_indexes(&row_info, png_ptr->row_buf + 1,
-        png_ptr->num_palette_max);
-#endif
-   if (png_ptr->num_palette_max > png_ptr->num_palette + 1)
-      png_warning(png_ptr, "Palette index exceeded num_palette");
 #endif
 
    /* Find a filter if necessary, filter the row and write it out. */