Update bundled libpng to version 1.6.17

Merged in the upstream version, which obsoleted many of the local
patches. The remaining diff to clean 1.6.17 is archived in the
qtpatches.diff file.

Change-Id: I5065435dc5a922d3f4a46eb37a23a4877dde2ee6
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@theqtcompany.com>

1 files changed, 124 insertions, 56 deletions

diff --git a/src/3rdparty/libpng/pngtrans.c b/src/3rdparty/libpng/pngtrans.c
index fef12f1851..cd3a79b6fa 100644
--- a/src/3rdparty/libpng/pngtrans.c
+++ b/src/3rdparty/libpng/pngtrans.c
@@ -1,8 +1,8 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.5.10 [March 8, 2012]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 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.)
  *
@@ -18,7 +18,7 @@
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 /* Turn on BGR-to-RGB mapping */
 void PNGAPI
-png_set_bgr(png_structp png_ptr)
+png_set_bgr(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_bgr");
 
@@ -32,7 +32,7 @@ png_set_bgr(png_structp png_ptr)
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* Turn on 16 bit byte swapping */
 void PNGAPI
-png_set_swap(png_structp png_ptr)
+png_set_swap(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_swap");
 
@@ -47,7 +47,7 @@ png_set_swap(png_structp png_ptr)
 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
 /* Turn on pixel packing */
 void PNGAPI
-png_set_packing(png_structp png_ptr)
+png_set_packing(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_packing");
 
@@ -57,7 +57,9 @@ png_set_packing(png_structp png_ptr)
    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;
-      png_ptr->usr_bit_depth = 8;
+#     ifdef PNG_WRITE_SUPPORTED
+         png_ptr->usr_bit_depth = 8;
+#     endif
    }
 }
 #endif
@@ -65,7 +67,7 @@ png_set_packing(png_structp png_ptr)
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 /* Turn on packed pixel swapping */
 void PNGAPI
-png_set_packswap(png_structp png_ptr)
+png_set_packswap(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_packswap");
 
@@ -79,7 +81,7 @@ png_set_packswap(png_structp png_ptr)
 
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 void PNGAPI
-png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)
+png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
 {
    png_debug(1, "in png_set_shift");
 
@@ -94,11 +96,11 @@ png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)
 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
     defined(PNG_WRITE_INTERLACING_SUPPORTED)
 int PNGAPI
-png_set_interlace_handling(png_structp png_ptr)
+png_set_interlace_handling(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_interlace handling");
 
-   if (png_ptr && png_ptr->interlaced)
+   if (png_ptr != 0 && png_ptr->interlaced != 0)
    {
       png_ptr->transformations |= PNG_INTERLACE;
       return (7);
@@ -115,44 +117,91 @@ png_set_interlace_handling(png_structp png_ptr)
  * that don't like bytes as parameters.
  */
 void PNGAPI
-png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 {
    png_debug(1, "in png_set_filler");
 
    if (png_ptr == NULL)
       return;
 
+   /* In libpng 1.6 it is possible to determine whether this is a read or write
+    * operation and therefore to do more checking here for a valid call.
+    */
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+   {
+#     ifdef PNG_READ_FILLER_SUPPORTED
+         /* On read png_set_filler is always valid, regardless of the base PNG
+          * format, because other transformations can give a format where the
+          * filler code can execute (basically an 8 or 16-bit component RGB or G
+          * format.)
+          *
+          * NOTE: usr_channels is not used by the read code!  (This has led to
+          * confusion in the past.)  The filler is only used in the read code.
+          */
+         png_ptr->filler = (png_uint_16)filler;
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on read");
+         PNG_UNUSED(filler) /* not used in the write case */
+         return;
+#     endif
+   }
+
+   else /* write */
+   {
+#     ifdef PNG_WRITE_FILLER_SUPPORTED
+         /* On write the usr_channels parameter must be set correctly at the
+          * start to record the number of channels in the app-supplied data.
+          */
+         switch (png_ptr->color_type)
+         {
+            case PNG_COLOR_TYPE_RGB:
+               png_ptr->usr_channels = 4;
+               break;
+
+            case PNG_COLOR_TYPE_GRAY:
+               if (png_ptr->bit_depth >= 8)
+               {
+                  png_ptr->usr_channels = 2;
+                  break;
+               }
+
+               else
+               {
+                  /* There simply isn't any code in libpng to strip out bits
+                   * from bytes when the components are less than a byte in
+                   * size!
+                   */
+                  png_app_error(png_ptr,
+                     "png_set_filler is invalid for low bit depth gray output");
+                  return;
+               }
+
+            default:
+               png_app_error(png_ptr,
+                  "png_set_filler: inappropriate color type");
+               return;
+         }
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on write");
+         return;
+#     endif
+   }
+
+   /* Here on success - libpng supports the operation, set the transformation
+    * and the flag to say where the filler channel is.
+    */
    png_ptr->transformations |= PNG_FILLER;
-   png_ptr->filler = (png_uint_16)filler;
 
    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
 
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
-
-   /* This should probably go in the "do_read_filler" routine.
-    * I attempted to do that in libpng-1.0.1a but that caused problems
-    * so I restored it in libpng-1.0.2a
-   */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
-   {
-      png_ptr->usr_channels = 4;
-   }
-
-   /* Also I added this in libpng-1.0.2a (what happens when we expand
-    * a less-than-8-bit grayscale to GA?) */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
-   {
-      png_ptr->usr_channels = 2;
-   }
 }
 
 /* Added to libpng-1.2.7 */
 void PNGAPI
-png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 {
    png_debug(1, "in png_set_add_alpha");
 
@@ -160,7 +209,9 @@ png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
       return;
 
    png_set_filler(png_ptr, filler, filler_loc);
-   png_ptr->transformations |= PNG_ADD_ALPHA;
+   /* The above may fail to do anything. */
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
+      png_ptr->transformations |= PNG_ADD_ALPHA;
 }
 
 #endif
@@ -168,7 +219,7 @@ png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
 void PNGAPI
-png_set_swap_alpha(png_structp png_ptr)
+png_set_swap_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_swap_alpha");
 
@@ -182,7 +233,7 @@ png_set_swap_alpha(png_structp png_ptr)
 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
 void PNGAPI
-png_set_invert_alpha(png_structp png_ptr)
+png_set_invert_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_invert_alpha");
 
@@ -195,7 +246,7 @@ png_set_invert_alpha(png_structp png_ptr)
 
 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
 void PNGAPI
-png_set_invert_mono(png_structp png_ptr)
+png_set_invert_mono(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_invert_mono");
 
@@ -276,9 +327,16 @@ png_do_swap(png_row_infop row_info, png_bytep row)
 
       for (i = 0; i < istop; i++, rp += 2)
       {
+#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
+         /* Feature added to libpng-1.6.11 for testing purposes, not
+          * enabled by default.
+          */
+         *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
+#else
          png_byte t = *rp;
          *rp = *(rp + 1);
          *(rp + 1) = t;
+#endif
       }
    }
 }
@@ -420,7 +478,7 @@ png_do_packswap(png_row_infop row_info, png_bytep row)
          *rp = table[*rp];
    }
 }
-#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */
+#endif /* PACKSWAP || WRITE_PACKSWAP */
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
@@ -452,7 +510,7 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
    {
       if (row_info->bit_depth == 8)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             ++sp;
          else          /* Skip initial channel and, for sp, the filler */
             sp += 2, ++dp;
@@ -466,7 +524,7 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             sp += 2;
          else          /* Skip initial channel and, for sp, the filler */
             sp += 4, dp += 2;
@@ -492,7 +550,7 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
    {
       if (row_info->bit_depth == 8)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             ++sp;
          else          /* Skip initial channels and, for sp, the filler */
             sp += 4, dp += 3;
@@ -506,7 +564,7 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             sp += 2;
          else          /* Skip initial channels and, for sp, the filler */
             sp += 8, dp += 6;
@@ -547,7 +605,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_bgr");
 
-   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       png_uint_32 row_width = row_info->width;
       if (row_info->bit_depth == 8)
@@ -617,16 +675,16 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
 #endif
    }
 }
-#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
+#endif /* READ_BGR || WRITE_BGR */
 
 #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_structp png_ptr, png_row_infop row_info)
+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->num_palette > 0) /* num_palette can be 0 in MNG files */
    {
       /* Calculations moved outside switch in an attempt to stop different
        * compiler warnings.  'padding' is in *bits* within the last byte, it is
@@ -708,7 +766,7 @@ png_do_check_palette_indexes(png_structp png_ptr, png_row_infop row_info)
          {
             for (; rp > png_ptr->row_buf; rp--)
             {
-               if (*rp >= png_ptr->num_palette_max)
+               if (*rp > png_ptr->num_palette_max)
                   png_ptr->num_palette_max = (int) *rp;
             }
 
@@ -720,19 +778,30 @@ png_do_check_palette_indexes(png_structp png_ptr, png_row_infop row_info)
       }
    }
 }
-#endif /* PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED */
+#endif /* CHECK_FOR_INVALID_INDEX */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
 void PNGAPI
-png_set_user_transform_info(png_structp png_ptr, png_voidp
+png_set_user_transform_info(png_structrp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)
 {
    png_debug(1, "in png_set_user_transform_info");
 
    if (png_ptr == NULL)
       return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+      (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+   {
+      png_app_error(png_ptr,
+            "info change after png_start_read_image or png_read_update_info");
+      return;
+   }
+#endif
+
    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;
@@ -746,20 +815,20 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
  */
 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
 png_voidp PNGAPI
-png_get_user_transform_ptr(png_const_structp png_ptr)
+png_get_user_transform_ptr(png_const_structrp png_ptr)
 {
    if (png_ptr == NULL)
       return (NULL);
 
-   return ((png_voidp)png_ptr->user_transform_ptr);
+   return png_ptr->user_transform_ptr;
 }
 #endif
 
 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
 png_uint_32 PNGAPI
-png_get_current_row_number(png_const_structp png_ptr)
+png_get_current_row_number(png_const_structrp png_ptr)
 {
-   /* See the comments in png.h - this is the sub-image row when reading and
+   /* See the comments in png.h - this is the sub-image row when reading an
     * interlaced image.
     */
    if (png_ptr != NULL)
@@ -769,13 +838,12 @@ png_get_current_row_number(png_const_structp png_ptr)
 }
 
 png_byte PNGAPI
-png_get_current_pass_number(png_const_structp png_ptr)
+png_get_current_pass_number(png_const_structrp png_ptr)
 {
    if (png_ptr != NULL)
       return png_ptr->pass;
    return 8; /* invalid */
 }
-#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */
-#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
-          PNG_WRITE_USER_TRANSFORM_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* USER_TRANSFORM_INFO */
+#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
+#endif /* READ || WRITE */