add APNG support patch, needed for firefox png support

package/libpng/Makefile

@@ -5,7 +5,7 @@ include ${TOPDIR}/rules.mk
 
 PKG_NAME:=		libpng
 PKG_VERSION:=		1.2.44
-PKG_RELEASE:=		1
+PKG_RELEASE:=		2
 PKG_MD5SUM:=		89b62f8daaeeab1342e307d6d1411ff1
 PKG_DESCR:=		A library for reading/writing PNG images
 PKG_SECTION:=		libs

package/libpng/patches/001-apng.patch

@@ -0,0 +1,1642 @@
+diff -Nur libpng-1.2.44.orig/png.c libpng-1.2.44/png.c
+--- libpng-1.2.44.orig/png.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/png.c	2010-07-08 21:21:33.745873377 +0200
+@@ -56,6 +56,11 @@
+ PNG_tIME;
+ PNG_tRNS;
+ PNG_zTXt;
++#ifdef PNG_APNG_SUPPORTED
++PNG_acTL;
++PNG_fcTL;
++PNG_fdAT;
++#endif
+ 
+ #ifdef PNG_READ_SUPPORTED
+ /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+diff -Nur libpng-1.2.44.orig/pngconf.h libpng-1.2.44/pngconf.h
+--- libpng-1.2.44.orig/pngconf.h	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngconf.h	2010-07-08 21:21:33.906029659 +0200
+@@ -951,6 +951,10 @@
+ #  define PNG_NO_READ_tEXt
+ #  define PNG_NO_READ_zTXt
+ #endif
++#ifndef PNG_NO_READ_APNG
++#  define PNG_READ_APNG_SUPPORTED
++#  define PNG_APNG_SUPPORTED
++#endif
+ #ifndef PNG_NO_READ_bKGD
+ #  define PNG_READ_bKGD_SUPPORTED
+ #  define PNG_bKGD_SUPPORTED
+@@ -1177,6 +1181,14 @@
+ #    define PNG_TEXT_SUPPORTED
+ #  endif
+ #endif
++#ifndef PNG_NO_WRITE_APNG
++#  ifndef PNG_WRITE_APNG_SUPPORTED
++#    define PNG_WRITE_APNG_SUPPORTED
++#  endif
++#  ifndef PNG_APNG_SUPPORTED
++#    define PNG_APNG_SUPPORTED
++#  endif
++#endif
+ 
+ #ifdef PNG_WRITE_tIME_SUPPORTED
+ #  ifndef PNG_NO_CONVERT_tIME
+diff -Nur libpng-1.2.44.orig/pngget.c libpng-1.2.44/pngget.c
+--- libpng-1.2.44.orig/pngget.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngget.c	2010-07-08 21:21:33.676118515 +0200
+@@ -842,6 +842,167 @@
+ }
+ #endif
+ 
++#ifdef PNG_APNG_SUPPORTED
++png_uint_32 PNGAPI
++png_get_acTL(png_structp png_ptr, png_infop info_ptr,
++             png_uint_32 *num_frames, png_uint_32 *num_plays)
++{
++    png_debug1(1, "in %s retrieval function", "acTL");
++    
++    if (png_ptr != NULL && info_ptr != NULL &&
++        (info_ptr->valid & PNG_INFO_acTL) &&
++        num_frames != NULL && num_plays != NULL)
++    {
++        *num_frames = info_ptr->num_frames;
++        *num_plays = info_ptr->num_plays;
++        return (1);
++    }
++    
++    return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_num_frames(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_num_frames()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->num_frames);
++    return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_num_plays(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_num_plays()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->num_plays);
++    return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
++             png_uint_32 *width, png_uint_32 *height,
++             png_uint_32 *x_offset, png_uint_32 *y_offset,
++             png_uint_16 *delay_num, png_uint_16 *delay_den,
++             png_byte *dispose_op, png_byte *blend_op)
++{
++    png_debug1(1, "in %s retrieval function", "fcTL");
++    
++    if (png_ptr != NULL && info_ptr != NULL &&
++        (info_ptr->valid & PNG_INFO_fcTL) &&
++        width != NULL && height != NULL && 
++        x_offset != NULL && x_offset != NULL && 
++        delay_num != NULL && delay_den != NULL &&
++        dispose_op != NULL && blend_op != NULL)
++    {
++        *width = info_ptr->next_frame_width;
++        *height = info_ptr->next_frame_height;
++        *x_offset = info_ptr->next_frame_x_offset;
++        *y_offset = info_ptr->next_frame_y_offset;
++        *delay_num = info_ptr->next_frame_delay_num;
++        *delay_den = info_ptr->next_frame_delay_den;
++        *dispose_op = info_ptr->next_frame_dispose_op;
++        *blend_op = info_ptr->next_frame_blend_op;
++        return (1);
++    }
++    
++    return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_width(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_width()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_width);
++    return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_height(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_height()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_height);
++    return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_x_offset(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_x_offset()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_x_offset);
++    return (0);
++}
++
++png_uint_32 PNGAPI
++png_get_next_frame_y_offset(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_y_offset()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_y_offset);
++    return (0);
++}
++
++png_uint_16 PNGAPI
++png_get_next_frame_delay_num(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_delay_num()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_delay_num);
++    return (0);
++}
++
++png_uint_16 PNGAPI
++png_get_next_frame_delay_den(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_delay_den()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_delay_den);
++    return (0);
++}
++
++png_byte PNGAPI
++png_get_next_frame_dispose_op(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_dispose_op()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_dispose_op);
++    return (0);
++}
++
++png_byte PNGAPI
++png_get_next_frame_blend_op(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_get_next_frame_blend_op()");
++    
++    if (png_ptr != NULL && info_ptr != NULL)
++        return (info_ptr->next_frame_blend_op);
++    return (0);
++}
++
++png_byte PNGAPI
++png_get_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_first_frame_is_hidden()");
++    
++    if (png_ptr != NULL)
++       return (png_byte)(png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN);
++    
++    return 0;
++}
++#endif /* PNG_APNG_SUPPORTED */
++
+ #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+ png_uint_32 PNGAPI
+ png_get_unknown_chunks(png_structp png_ptr, png_infop info_ptr,
+diff -Nur libpng-1.2.44.orig/png.h libpng-1.2.44/png.h
+--- libpng-1.2.44.orig/png.h	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/png.h	2010-07-08 21:21:33.796029652 +0200
+@@ -1041,6 +1041,19 @@
+    png_fixed_point int_y_blue PNG_DEPSTRUCT;
+ #endif
+ 
++#ifdef PNG_APNG_SUPPORTED
++   png_uint_32 num_frames; /* including default image */
++   png_uint_32 num_plays;
++   png_uint_32 next_frame_width;
++   png_uint_32 next_frame_height;
++   png_uint_32 next_frame_x_offset;
++   png_uint_32 next_frame_y_offset;
++   png_uint_16 next_frame_delay_num;
++   png_uint_16 next_frame_delay_den;
++   png_byte next_frame_dispose_op;
++   png_byte next_frame_blend_op;
++#endif
++
+ } png_info;
+ 
+ typedef png_info FAR * png_infop;
+@@ -1142,6 +1155,10 @@
+ #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
+ #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
+ #define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
++#ifdef PNG_APNG_SUPPORTED
++#define PNG_INFO_acTL 0x10000L
++#define PNG_INFO_fcTL 0x20000L
++#endif
+ 
+ /* This is used for the transformation routines, as some of them
+  * change these values for the row.  It also should enable using
+@@ -1182,6 +1199,10 @@
+ typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
+ typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
+    png_uint_32, int));
++#ifdef PNG_APNG_SUPPORTED
++typedef void (PNGAPI *png_progressive_frame_ptr) PNGARG((png_structp, 
++   png_uint_32));
++#endif
+ #endif
+ 
+ #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+@@ -1527,6 +1548,39 @@
+    png_uint_32 user_height_max PNG_DEPSTRUCT;
+ #endif
+ 
++#ifdef PNG_APNG_SUPPORTED
++   png_uint_32 apng_flags;
++   png_uint_32 next_seq_num;         /* next fcTL/fdAT chunk sequence number */
++   png_uint_32 first_frame_width;
++   png_uint_32 first_frame_height;
++
++#ifdef PNG_READ_APNG_SUPPORTED
++   png_uint_32 num_frames_read;      /* incremented after all image data of */
++                                     /* a frame is read */
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++   png_progressive_frame_ptr frame_info_fn; /* frame info read callback */
++   png_progressive_frame_ptr frame_end_fn;  /* frame data read callback */
++#endif
++#endif
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   png_uint_32 num_frames_to_write;
++   png_uint_32 num_frames_written;
++#endif
++
++/* For png_struct.apng_flags: */
++#define PNG_FIRST_FRAME_HIDDEN       0x0001
++
++/* dispose_op flags from inside fcTL */
++#define PNG_DISPOSE_OP_NONE        0x00
++#define PNG_DISPOSE_OP_BACKGROUND  0x01
++#define PNG_DISPOSE_OP_PREVIOUS    0x02
++
++/* blend_op flags from inside fcTL */
++#define PNG_BLEND_OP_SOURCE        0x00
++#define PNG_BLEND_OP_OVER          0x01
++#endif /* PNG_APNG_SUPPORTED */
++
+ /* New member added in libpng-1.0.25 and 1.2.17 */
+ #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+    /* Storage for unknown chunk that the library doesn't recognize. */
+@@ -1861,6 +1915,18 @@
+ extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
+    png_bytepp image));
+ 
++#ifdef PNG_WRITE_APNG_SUPPORTED
++extern PNG_EXPORT (void,png_write_frame_head) PNGARG((png_structp png_ptr,
++   png_infop png_info, png_bytepp row_pointers,
++   png_uint_32 width, png_uint_32 height,
++   png_uint_32 x_offset, png_uint_32 y_offset, 
++   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++   png_byte blend_op));
++
++extern PNG_EXPORT (void,png_write_frame_tail) PNGARG((png_structp png_ptr,
++   png_infop png_info));
++#endif
++   
+ /* Writes the end of the PNG file. */
+ extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
+    png_infop info_ptr));
+@@ -2114,6 +2180,11 @@
+    png_voidp progressive_ptr,
+    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+    png_progressive_end_ptr end_fn));
++#ifdef PNG_READ_APNG_SUPPORTED
++extern PNG_EXPORT(void,png_set_progressive_frame_fn) PNGARG((png_structp png_ptr,
++   png_progressive_frame_ptr frame_info_fn,
++   png_progressive_frame_ptr frame_end_fn));
++#endif
+ 
+ /* Returns the user pointer associated with the push read functions */
+ extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
+@@ -2554,6 +2625,59 @@
+ #endif
+ #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
+ 
++#ifdef PNG_APNG_SUPPORTED
++extern PNG_EXPORT(png_uint_32,png_get_acTL) PNGARG((png_structp png_ptr,
++   png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));
++extern PNG_EXPORT(png_uint_32,png_set_acTL) PNGARG((png_structp png_ptr, 
++   png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));
++extern PNG_EXPORT(png_uint_32,png_get_num_frames) PNGARG((png_structp png_ptr,
++   png_infop info_ptr));
++extern PNG_EXPORT(png_uint_32,png_get_num_plays) 
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++
++extern PNG_EXPORT(png_uint_32,png_get_next_frame_fcTL) 
++   PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 *width, 
++   png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset, 
++   png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,
++   png_byte *blend_op));
++extern PNG_EXPORT(png_uint_32,png_set_next_frame_fcTL) 
++   PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 width, 
++   png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset, 
++   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++   png_byte blend_op));
++extern PNG_EXPORT(void,png_ensure_fcTL_is_valid)
++   PNGARG((png_structp png_ptr,
++   png_uint_32 width, png_uint_32 height,
++   png_uint_32 x_offset, png_uint_32 y_offset,
++   png_uint_16 delay_num, png_uint_16 delay_den,
++   png_byte dispose_op, png_byte blend_op));
++extern PNG_EXPORT(png_uint_32,png_get_next_frame_width)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_uint_32,png_get_next_frame_height)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_uint_32,png_get_next_frame_x_offset)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_uint_32,png_get_next_frame_y_offset)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_uint_16,png_get_next_frame_delay_num)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_uint_16,png_get_next_frame_delay_den)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_byte,png_get_next_frame_dispose_op)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_byte,png_get_next_frame_blend_op)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_byte,png_get_first_frame_is_hidden)
++   PNGARG((png_structp png_ptr, png_infop info_ptr));
++extern PNG_EXPORT(png_uint_32,png_set_first_frame_is_hidden)
++   PNGARG((png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));
++#endif /* PNG_APNG_SUPPORTED */
++
++#ifdef PNG_READ_APNG_SUPPORTED
++extern PNG_EXPORT(void,png_read_frame_head) PNGARG((png_structp png_ptr,
++   png_infop info_ptr));
++#endif
++
+ #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ /* Provide a list of chunks and how they are to be handled, if the built-in
+    handling or default unknown chunk handling is not desired.  Any chunks not
+@@ -2918,6 +3042,10 @@
+ #define PNG_BACKGROUND_IS_GRAY     0x800
+ #define PNG_HAVE_PNG_SIGNATURE    0x1000
+ #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
++#ifdef PNG_APNG_SUPPORTED
++#define PNG_HAVE_acTL             0x4000
++#define PNG_HAVE_fcTL             0x8000L
++#endif
+ 
+ /* Flags for the transformations the PNG library does on the image data */
+ #define PNG_BGR                0x0001
+@@ -3060,6 +3188,11 @@
+ #define PNG_tIME png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
+ #define PNG_tRNS png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
+ #define PNG_zTXt png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
++#ifdef PNG_APNG_SUPPORTED
++#define PNG_acTL png_byte png_acTL[5] = { 97,  99,  84,  76, '\0'}
++#define PNG_fcTL png_byte png_fcTL[5] = {102,  99,  84,  76, '\0'}
++#define PNG_fdAT png_byte png_fdAT[5] = {102, 100,  65,  84, '\0'}
++#endif
+ 
+ #ifdef PNG_USE_GLOBAL_ARRAYS
+ PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
+@@ -3083,6 +3216,11 @@
+ PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
+ PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
+ PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
++#ifdef PNG_APNG_SUPPORTED
++PNG_EXPORT_VAR (png_byte FARDATA) png_acTL[5];
++PNG_EXPORT_VAR (png_byte FARDATA) png_fcTL[5];
++PNG_EXPORT_VAR (png_byte FARDATA) png_fdAT[5];
++#endif
+ #endif /* PNG_USE_GLOBAL_ARRAYS */
+ 
+ #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
+@@ -3365,6 +3503,17 @@
+ #endif
+ #endif
+ 
++#ifdef PNG_WRITE_APNG_SUPPORTED
++PNG_EXTERN void png_write_acTL PNGARG((png_structp png_ptr,
++   png_uint_32 num_frames, png_uint_32 num_plays));
++
++PNG_EXTERN void png_write_fcTL PNGARG((png_structp png_ptr, 
++   png_uint_32 width, png_uint_32 height, 
++   png_uint_32 x_offset, png_uint_32 y_offset, 
++   png_uint_16 delay_num, png_uint_16 delay_den,
++   png_byte dispose_op, png_byte blend_op));
++#endif
++
+ /* Called when finished processing a row of data */
+ PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
+ 
+@@ -3417,6 +3566,20 @@
+ PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
+    png_infop info_ptr)) PNG_PRIVATE;
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++/* Private, reset some things to become ready for reading next frame */
++PNG_EXTERN void png_read_reset PNGARG((png_structp png_ptr));
++PNG_EXTERN void png_read_reinit PNGARG((png_structp png_ptr,
++   png_infop info_ptr));
++PNG_EXTERN void png_progressive_read_reset PNGARG((png_structp png_ptr));
++#endif
++#ifdef PNG_WRITE_APNG_SUPPORTED
++/* Private, reset some things to become ready for writing next frame */
++PNG_EXTERN void png_write_reset PNGARG((png_structp png_ptr));
++PNG_EXTERN void png_write_reinit PNGARG((png_structp png_ptr, 
++   png_infop info_ptr, png_uint_32 width, png_uint_32 height));
++#endif
++
+ /* These are the functions that do the transformations */
+ #ifdef PNG_READ_FILLER_SUPPORTED
+ PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
+@@ -3640,6 +3803,18 @@
+    png_uint_32 length)) PNG_PRIVATE;
+ #endif
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++PNG_EXTERN void png_handle_acTL PNGARG((png_structp png_ptr, png_infop info_ptr,
++   png_uint_32 length));
++PNG_EXTERN void png_handle_fcTL PNGARG((png_structp png_ptr, png_infop info_ptr,
++   png_uint_32 length));
++PNG_EXTERN void png_have_info PNGARG((png_structp png_ptr, png_infop info_ptr));
++PNG_EXTERN void png_handle_fdAT PNGARG((png_structp png_ptr, png_infop info_ptr,
++   png_uint_32 length));
++PNG_EXTERN void png_ensure_sequence_number PNGARG((png_structp png_ptr, 
++   png_uint_32 length));
++#endif
++
+ PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
+    png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
+ 
+diff -Nur libpng-1.2.44.orig/pngpread.c libpng-1.2.44/pngpread.c
+--- libpng-1.2.44.orig/pngpread.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngpread.c	2010-07-08 21:21:33.947205863 +0200
+@@ -206,6 +206,11 @@
+ #ifdef PNG_READ_zTXt_SUPPORTED
+       PNG_CONST PNG_zTXt;
+ #endif
++#ifdef PNG_READ_APNG_SUPPORTED
++      PNG_CONST PNG_acTL;
++      PNG_CONST PNG_fcTL;
++      PNG_CONST PNG_fdAT;
++#endif
+ #endif /* PNG_USE_LOCAL_ARRAYS */
+ 
+    /* First we make sure we have enough data for the 4 byte chunk name
+@@ -232,6 +237,103 @@
+       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+    }
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++   if (png_ptr->num_frames_read > 0 && 
++       png_ptr->num_frames_read < info_ptr->num_frames)
++   {
++      if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
++      {
++         /* Discard trailing IDATs for the first frame */
++         if (png_ptr->mode & PNG_HAVE_fcTL || png_ptr->num_frames_read > 1)
++            png_error(png_ptr, "out of place IDAT");
++         
++         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++         {
++            png_push_save_buffer(png_ptr);
++            return;
++         }
++         png_push_crc_skip(png_ptr, png_ptr->push_length);
++         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++         return;
++      }
++      else if (!png_memcmp(png_ptr->chunk_name, png_fdAT, 4))
++      {
++         if (png_ptr->buffer_size < 4)
++         {
++            png_push_save_buffer(png_ptr);
++            return;
++         }
++         png_ensure_sequence_number(png_ptr, 4);
++         
++         if (!(png_ptr->mode & PNG_HAVE_fcTL))
++         {
++            /* Discard trailing fdATs for frames other than the first */
++            if (png_ptr->num_frames_read < 2)
++               png_error(png_ptr, "out of place fdAT");
++            
++            if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++            {
++               png_push_save_buffer(png_ptr);
++               return;
++            }
++            png_push_crc_skip(png_ptr, png_ptr->push_length);
++            png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++            return;
++         }
++         else
++         {
++            /* frame data follows */
++            png_ptr->idat_size = png_ptr->push_length - 4;
++            png_ptr->mode |= PNG_HAVE_IDAT;
++            png_ptr->process_mode = PNG_READ_IDAT_MODE;
++            
++            return;
++         }
++      }
++      else if(!png_memcmp(png_ptr->chunk_name, png_fcTL, 4))
++      {
++         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++         {
++            png_push_save_buffer(png_ptr);
++            return;
++         }
++         
++         png_read_reset(png_ptr);
++         png_ptr->mode &= ~PNG_HAVE_fcTL;
++         
++         png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
++         
++         if (!(png_ptr->mode & PNG_HAVE_fcTL))
++            png_error(png_ptr, "missing required fcTL chunk");
++         
++         png_read_reinit(png_ptr, info_ptr);
++         png_progressive_read_reset(png_ptr);
++         
++         if (png_ptr->frame_info_fn != NULL)
++            (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read);
++         
++         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++         
++         return;
++      }
++      else
++      {
++         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++         {
++            png_push_save_buffer(png_ptr);
++            return;
++         }
++         png_warning(png_ptr, "Skipped (ignored) a chunk "
++                              "between APNG chunks");
++         png_push_crc_skip(png_ptr, png_ptr->push_length);
++         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++         return;
++      }
++      
++      return;
++   }
++#endif /* PNG_READ_APNG_SUPPORTED */
++
+    if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      if (png_ptr->mode & PNG_AFTER_IDAT)
+         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+@@ -327,6 +429,9 @@
+             png_error(png_ptr, "Too many IDAT's found");
+       }
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++      png_have_info(png_ptr, info_ptr);
++#endif
+       png_ptr->idat_size = png_ptr->push_length;
+       png_ptr->mode |= PNG_HAVE_IDAT;
+       png_ptr->process_mode = PNG_READ_IDAT_MODE;
+@@ -559,6 +664,38 @@
+    }
+ 
+ #endif
++#ifdef PNG_READ_APNG_SUPPORTED
++   else if (!png_memcmp(png_ptr->chunk_name, png_acTL, 4))
++   {
++      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++      {
++         png_push_save_buffer(png_ptr);
++         return;
++      }
++
++      png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length);
++   }
++   else if (!png_memcmp(png_ptr->chunk_name, png_fcTL, 4))
++   {
++      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++      {
++         png_push_save_buffer(png_ptr);
++         return;
++      }
++
++      png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
++   }
++   else if (!png_memcmp(png_ptr->chunk_name, png_fdAT, 4))
++   {
++      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++      {
++         png_push_save_buffer(png_ptr);
++         return;
++      }
++
++      png_handle_fdAT(png_ptr, info_ptr, png_ptr->push_length);
++   }
++#endif /* PNG_READ_APNG_SUPPORTED */
+    else
+    {
+       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+@@ -738,13 +875,17 @@
+ png_push_read_IDAT(png_structp png_ptr)
+ {
+ #ifdef PNG_USE_LOCAL_ARRAYS
+-   PNG_CONST PNG_IDAT;
++   PNG_IDAT;
++#ifdef PNG_READ_APNG_SUPPORTED
++   PNG_fdAT;
++   PNG_IEND;
++#endif
+ #endif
+    if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+    {
+       png_byte chunk_length[4];
+ 
+-      if (png_ptr->buffer_size < 8)
++      if (png_ptr->buffer_size < 12)
+       {
+          png_push_save_buffer(png_ptr);
+          return;
+@@ -756,15 +897,62 @@
+       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+ 
+-      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
++#ifdef PNG_READ_APNG_SUPPORTED
++      if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_fdAT, 4)
++          && png_ptr->num_frames_read > 0)
++      {
++          if (png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)
++          {
++              png_ptr->process_mode = PNG_READ_CHUNK_MODE;
++              if (png_ptr->frame_end_fn != NULL)
++                 (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
++              png_ptr->num_frames_read++;
++              return;
++          }
++          else
++          {
++              if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
++                  png_error(png_ptr, "Not enough image data");
++              if (png_ptr->push_length + 4 > png_ptr->buffer_size)
++              {
++                 png_push_save_buffer(png_ptr);
++                 return;
++              }
++              png_warning(png_ptr, "Skipping (ignoring) a chunk between "
++                                   "APNG chunks");
++              png_crc_finish(png_ptr, png_ptr->push_length);
++              png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++              return;
++          }
++      }
++      else 
++#endif
++      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)
++#ifdef PNG_READ_APNG_SUPPORTED
++                && (png_ptr->num_frames_read == 0)
++#endif
++         )
+       {
+          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+          if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+             png_error(png_ptr, "Not enough compressed data");
++#ifdef PNG_READ_APNG_SUPPORTED
++         if (png_ptr->frame_end_fn != NULL)
++            (*(png_ptr->frame_end_fn))(png_ptr, png_ptr->num_frames_read);
++         png_ptr->num_frames_read++;
++#endif
+          return;
+       }
+ 
+       png_ptr->idat_size = png_ptr->push_length;
++
++#ifdef PNG_READ_APNG_SUPPORTED
++      if (png_ptr->num_frames_read > 0)
++      {
++         png_ensure_sequence_number(png_ptr, 4);
++         png_ptr->idat_size -= 4;
++      }
++#endif
+    }
+    if (png_ptr->idat_size && png_ptr->save_buffer_size)
+    {
+@@ -1763,6 +1951,17 @@
+    png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
+ }
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++void PNGAPI
++png_set_progressive_frame_fn(png_structp png_ptr,
++   png_progressive_frame_ptr frame_info_fn,
++   png_progressive_frame_ptr frame_end_fn)
++{
++   png_ptr->frame_info_fn = frame_info_fn;
++   png_ptr->frame_end_fn = frame_end_fn;
++}
++#endif
++
+ png_voidp PNGAPI
+ png_get_progressive_ptr(png_structp png_ptr)
+ {
+diff -Nur libpng-1.2.44.orig/pngread.c libpng-1.2.44/pngread.c
+--- libpng-1.2.44.orig/pngread.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngread.c	2010-07-08 21:21:33.676118515 +0200
+@@ -437,6 +437,11 @@
+ #ifdef PNG_READ_zTXt_SUPPORTED
+       PNG_CONST PNG_zTXt;
+ #endif
++#ifdef PNG_READ_APNG_SUPPORTED
++      PNG_CONST PNG_acTL;
++      PNG_CONST PNG_fcTL;
++      PNG_CONST PNG_fdAT;
++#endif
+ #endif /* PNG_USE_LOCAL_ARRAYS */
+       png_uint_32 length = png_read_chunk_header(png_ptr);
+       PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+@@ -481,6 +486,9 @@
+                   !(png_ptr->mode & PNG_HAVE_PLTE))
+             png_error(png_ptr, "Missing PLTE before IDAT");
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++         png_have_info(png_ptr, info_ptr);
++#endif
+          png_ptr->idat_size = length;
+          png_ptr->mode |= PNG_HAVE_IDAT;
+          break;
+@@ -553,12 +561,97 @@
+       else if (!png_memcmp(chunk_name, png_iTXt, 4))
+          png_handle_iTXt(png_ptr, info_ptr, length);
+ #endif
++#ifdef PNG_READ_APNG_SUPPORTED
++      else if (!png_memcmp(chunk_name, png_acTL, 4))
++         png_handle_acTL(png_ptr, info_ptr, length);
++      else if (!png_memcmp(chunk_name, png_fcTL, 4))
++         png_handle_fcTL(png_ptr, info_ptr, length);
++      else if (!png_memcmp(chunk_name, png_fdAT, 4))
++         png_handle_fdAT(png_ptr, info_ptr, length);
++#endif
+       else
+          png_handle_unknown(png_ptr, info_ptr, length);
+    }
+ }
+ #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++void PNGAPI
++png_read_frame_head(png_structp png_ptr, png_infop info_ptr)
++{
++    png_byte have_chunk_after_DAT; /* after IDAT or after fdAT */
++    
++    png_debug(0, "Reading frame head");
++    
++    if (!(png_ptr->mode & PNG_HAVE_acTL))
++        png_error(png_ptr, "attempt to png_read_frame_head() but "
++                           "no acTL present");
++    
++    /* do nothing for the main IDAT */
++    if (png_ptr->num_frames_read == 0)
++        return;
++    
++    png_crc_finish(png_ptr, 0); /* CRC from last IDAT or fdAT chunk */
++    
++    png_read_reset(png_ptr);
++    png_ptr->mode &= ~PNG_HAVE_fcTL;
++    
++    have_chunk_after_DAT = 0;
++    for (;;)
++    {
++#ifdef PNG_USE_LOCAL_ARRAYS
++        PNG_IDAT;
++        PNG_fdAT;
++        PNG_fcTL;
++#endif
++        png_byte chunk_length[4];
++        png_uint_32 length;
++        
++        png_read_data(png_ptr, chunk_length, 4);
++        length = png_get_uint_31(png_ptr, chunk_length);
++        
++        png_reset_crc(png_ptr);
++        png_crc_read(png_ptr, png_ptr->chunk_name, 4);
++        
++        if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
++        {
++            /* discard trailing IDATs for the first frame */
++            if (have_chunk_after_DAT || png_ptr->num_frames_read > 1)
++                png_error(png_ptr, "png_read_frame_head(): out of place IDAT");
++            png_crc_finish(png_ptr, length);
++        }
++        else if (!png_memcmp(png_ptr->chunk_name, png_fcTL, 4))
++        {
++            png_handle_fcTL(png_ptr, info_ptr, length);
++            have_chunk_after_DAT = 1;
++        }
++        else if (!png_memcmp(png_ptr->chunk_name, png_fdAT, 4))
++        {
++            png_ensure_sequence_number(png_ptr, length);
++            
++            /* discard trailing fdATs for frames other than the first */
++            if (!have_chunk_after_DAT && png_ptr->num_frames_read > 1)
++                png_crc_finish(png_ptr, length - 4);
++            else if(png_ptr->mode & PNG_HAVE_fcTL)
++            {
++                png_ptr->idat_size = length - 4;
++                png_ptr->mode |= PNG_HAVE_IDAT;
++                
++                break;
++            }
++            else
++                png_error(png_ptr, "png_read_frame_head(): out of place fdAT");
++        }
++        else
++        {
++            png_warning(png_ptr, "Skipped (ignored) a chunk "
++                                 "between APNG chunks");
++            png_crc_finish(png_ptr, length);
++        }
++    }
++}
++#endif /* PNG_READ_APNG_SUPPORTED */
++
+ /* Optional call to update the users info_ptr structure */
+ void PNGAPI
+ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
+@@ -599,6 +692,10 @@
+ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
+ {
+    PNG_CONST PNG_IDAT;
++#ifdef PNG_READ_APNG_SUPPORTED
++   PNG_CONST PNG_fdAT;
++   PNG_CONST PNG_IEND;
++#endif
+    PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
+       0xff};
+    PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+@@ -734,13 +831,39 @@
+    {
+       if (!(png_ptr->zstream.avail_in))
+       {
+-         while (!png_ptr->idat_size)
++         png_uint_32 bytes_to_skip = 0;
++
++         while (!png_ptr->idat_size || bytes_to_skip != 0)
+          {
+-            png_crc_finish(png_ptr, 0);
++            png_crc_finish(png_ptr, bytes_to_skip);
++            bytes_to_skip = 0;
+ 
+             png_ptr->idat_size = png_read_chunk_header(png_ptr);
++#ifdef PNG_READ_APNG_SUPPORTED
++            if (png_ptr->num_frames_read == 0)
++            {
++#endif
+             if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+                png_error(png_ptr, "Not enough image data");
++#ifdef PNG_READ_APNG_SUPPORTED
++            }
++            else
++            {
++               if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
++                  png_error(png_ptr, "Not enough image data");
++               if (png_memcmp(png_ptr->chunk_name, png_fdAT, 4))
++               {
++                  png_warning(png_ptr, "Skipped (ignored) a chunk "
++                                       "between APNG chunks");
++                  bytes_to_skip = png_ptr->idat_size;
++                  continue;
++               }
++               
++               png_ensure_sequence_number(png_ptr, png_ptr->idat_size);
++               
++               png_ptr->idat_size -= 4;
++            }
++#endif
+          }
+          png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
+          png_ptr->zstream.next_in = png_ptr->zbuf;
+@@ -758,6 +881,9 @@
+             png_error(png_ptr, "Extra compressed data");
+          png_ptr->mode |= PNG_AFTER_IDAT;
+          png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
++#ifdef PNG_READ_APNG_SUPPORTED
++         png_ptr->num_frames_read++;
++#endif
+          break;
+       }
+       if (ret != Z_OK)
+@@ -1015,6 +1141,11 @@
+ #ifdef PNG_READ_zTXt_SUPPORTED
+       PNG_CONST PNG_zTXt;
+ #endif
++#ifdef PNG_READ_APNG_SUPPORTED
++      PNG_CONST PNG_acTL;
++      PNG_CONST PNG_fcTL;
++      PNG_CONST PNG_fdAT;
++#endif
+ #endif /* PNG_USE_LOCAL_ARRAYS */
+       png_uint_32 length = png_read_chunk_header(png_ptr);
+       PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
+@@ -1115,6 +1246,14 @@
+       else if (!png_memcmp(chunk_name, png_iTXt, 4))
+          png_handle_iTXt(png_ptr, info_ptr, length);
+ #endif
++#ifdef PNG_READ_APNG_SUPPORTED
++      else if (!png_memcmp(chunk_name, png_acTL, 4))
++         png_handle_acTL(png_ptr, info_ptr, length);
++      else if (!png_memcmp(chunk_name, png_fcTL, 4))
++         png_handle_fcTL(png_ptr, info_ptr, length);
++      else if (!png_memcmp(chunk_name, png_fdAT, 4))
++         png_handle_fdAT(png_ptr, info_ptr, length);
++#endif
+       else
+          png_handle_unknown(png_ptr, info_ptr, length);
+    } while (!(png_ptr->mode & PNG_HAVE_IEND));
+diff -Nur libpng-1.2.44.orig/pngrtran.c libpng-1.2.44/pngrtran.c
+--- libpng-1.2.44.orig/pngrtran.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngrtran.c	2010-07-08 21:21:34.149609181 +0200
+@@ -1352,7 +1352,7 @@
+        * pixels.  This check added to libpng-1.2.19
+        */
+ #if (PNG_WARN_UNINITIALIZED_ROW==1)
+-      png_error(png_ptr, "Uninitialized row");
++      png_warning(png_ptr, "Uninitialized row");
+ #else
+       png_warning(png_ptr, "Uninitialized row");
+ #endif
+diff -Nur libpng-1.2.44.orig/pngrutil.c libpng-1.2.44/pngrutil.c
+--- libpng-1.2.44.orig/pngrutil.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngrutil.c	2010-07-08 21:21:34.045873588 +0200
+@@ -460,6 +460,11 @@
+    filter_type = buf[11];
+    interlace_type = buf[12];
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++   png_ptr->first_frame_width = width;
++   png_ptr->first_frame_height = height;
++#endif
++
+    /* Set internal variables */
+    png_ptr->width = width;
+    png_ptr->height = height;
+@@ -2348,6 +2353,172 @@
+ }
+ #endif
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++void /* PRIVATE */
++png_handle_acTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
++{
++    png_byte data[8];
++    png_uint_32 num_frames;
++    png_uint_32 num_plays;
++    png_uint_32 didSet;
++    
++    png_debug(1, "in png_handle_acTL");
++
++    if (!(png_ptr->mode & PNG_HAVE_IHDR))
++    {
++        png_error(png_ptr, "Missing IHDR before acTL");
++    }
++    else if (png_ptr->mode & PNG_HAVE_IDAT)
++    {
++        png_warning(png_ptr, "Invalid acTL after IDAT skipped");
++        png_crc_finish(png_ptr, length);
++        return;
++    }
++    else if (png_ptr->mode & PNG_HAVE_acTL)
++    {
++        png_warning(png_ptr, "Duplicate acTL skipped");
++        png_crc_finish(png_ptr, length);
++        return;
++    }
++    else if (length != 8)
++    {
++        png_warning(png_ptr, "acTL with invalid length skipped");
++        png_crc_finish(png_ptr, length);
++        return;
++    }
++    
++    png_crc_read(png_ptr, data, 8);
++    png_crc_finish(png_ptr, 0);
++    
++    num_frames = png_get_uint_31(png_ptr, data);
++    num_plays = png_get_uint_31(png_ptr, data + 4);
++    
++    /* the set function will do error checking on num_frames */
++    didSet = png_set_acTL(png_ptr, info_ptr, num_frames, num_plays);
++    if(didSet)
++        png_ptr->mode |= PNG_HAVE_acTL;
++}
++
++void /* PRIVATE */
++png_handle_fcTL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
++{
++    png_byte data[22];
++    png_uint_32 width;
++    png_uint_32 height;
++    png_uint_32 x_offset;
++    png_uint_32 y_offset;
++    png_uint_16 delay_num;
++    png_uint_16 delay_den;
++    png_byte dispose_op;
++    png_byte blend_op;
++
++    png_debug(1, "in png_handle_fcTL");
++
++    png_ensure_sequence_number(png_ptr, length);
++
++    if (!(png_ptr->mode & PNG_HAVE_IHDR))
++    {
++        png_error(png_ptr, "Missing IHDR before fcTL");
++    }
++    else if (png_ptr->mode & PNG_HAVE_IDAT)
++    {
++        /* for any frames other then the first this message may be misleading,
++        * but correct. PNG_HAVE_IDAT is unset before the frame head is read
++        * i can't think of a better message */
++        png_warning(png_ptr, "Invalid fcTL after IDAT skipped");
++        png_crc_finish(png_ptr, length-4);
++        return;
++    }
++    else if (png_ptr->mode & PNG_HAVE_fcTL)
++    {
++        png_warning(png_ptr, "Duplicate fcTL within one frame skipped");
++        png_crc_finish(png_ptr, length-4);
++        return;
++    }
++    else if (length != 26)
++    {
++        png_warning(png_ptr, "fcTL with invalid length skipped");
++        png_crc_finish(png_ptr, length-4);
++        return;
++    }
++
++    png_crc_read(png_ptr, data, 22);
++    png_crc_finish(png_ptr, 0);
++
++    width = png_get_uint_31(png_ptr, data);
++    height = png_get_uint_31(png_ptr, data + 4);
++    x_offset = png_get_uint_31(png_ptr, data + 8);
++    y_offset = png_get_uint_31(png_ptr, data + 12);
++    delay_num = png_get_uint_16(data + 16);
++    delay_den = png_get_uint_16(data + 18);
++    dispose_op = data[20];
++    blend_op = data[21];
++
++    if (png_ptr->num_frames_read == 0 && (x_offset != 0 || y_offset != 0))
++        png_error(png_ptr, "fcTL for the first frame must have zero offset");
++
++    if (info_ptr != NULL)
++    {
++        if (png_ptr->num_frames_read == 0 &&
++            (width != info_ptr->width || height != info_ptr->height))
++            png_error(png_ptr, "size in first frame's fcTL must match "
++                               "the size in IHDR");
++
++        /* the set function will do more error checking */
++        png_set_next_frame_fcTL(png_ptr, info_ptr, width, height,
++                                x_offset, y_offset, delay_num, delay_den,
++                                dispose_op, blend_op);
++
++        png_read_reinit(png_ptr, info_ptr);
++    }
++
++    png_ptr->mode |= PNG_HAVE_fcTL;
++}
++
++void /* PRIVATE */
++png_have_info(png_structp png_ptr, png_infop info_ptr)
++{
++    if((info_ptr->valid & PNG_INFO_acTL) && !(info_ptr->valid & PNG_INFO_fcTL))
++    {
++        png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
++        info_ptr->num_frames++;
++    }
++}
++
++void /* PRIVATE */
++png_handle_fdAT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
++{
++    png_ensure_sequence_number(png_ptr, length);
++    
++    /* This function is only called from png_read_end(), png_read_info(), 
++    * and png_push_read_chunk() which means that:
++    * - the user doesn't want to read this frame
++    * - or this is an out-of-place fdAT
++    * in either case it is safe to ignore the chunk with a warning */
++    png_warning(png_ptr, "ignoring fdAT chunk");
++    png_crc_finish(png_ptr, length - 4);
++}
++
++void /* PRIVATE */
++png_ensure_sequence_number(png_structp png_ptr, png_uint_32 length)
++{
++    png_byte data[4];
++    png_uint_32 sequence_number;
++    
++    if (length < 4)
++        png_error(png_ptr, "invalid fcTL or fdAT chunk found");
++    
++    png_crc_read(png_ptr, data, 4);
++    sequence_number = png_get_uint_31(png_ptr, data);
++    
++    if (sequence_number != png_ptr->next_seq_num)
++        png_error(png_ptr, "fcTL or fdAT chunk with out-of-order sequence "
++                           "number found");
++    
++    png_ptr->next_seq_num++;
++}
++#endif /* PNG_READ_APNG_SUPPORTED */
++
+ /* This function is called when we haven't found a handler for a
+    chunk.  If there isn't a problem with the chunk itself (ie bad
+    chunk name, CRC, or a critical chunk), the chunk is silently ignored
+@@ -3379,4 +3550,75 @@
+ 
+    png_ptr->flags |= PNG_FLAG_ROW_INIT;
+ }
++
++#ifdef PNG_READ_APNG_SUPPORTED
++/* This function is to be called after the main IDAT set has been read and
++ * before a new IDAT is read. It resets some parts of png_ptr
++ * to make them usable by the read functions again */
++void /* PRIVATE */
++png_read_reset(png_structp png_ptr)
++{
++    png_ptr->mode &= ~PNG_HAVE_IDAT;
++    png_ptr->mode &= ~PNG_AFTER_IDAT;
++    png_ptr->row_number = 0;
++    png_ptr->pass = 0;
++    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
++}
++
++void /* PRIVATE */
++png_read_reinit(png_structp png_ptr, png_infop info_ptr)
++{
++    png_ptr->width = info_ptr->next_frame_width;
++    png_ptr->height = info_ptr->next_frame_height;
++    png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
++    if (png_ptr->prev_row)
++       png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
++}
++
++/* same as png_read_reset() but for the progressive reader */
++void /* PRIVATE */
++png_progressive_read_reset(png_structp png_ptr)
++{
++#ifdef PNG_USE_LOCAL_ARRAYS
++    /* start of interlace block */
++    const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
++
++    /* offset to next interlace block */
++    const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
++
++    /* start of interlace block in the y direction */
++    const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
++
++    /* offset to next interlace block in the y direction */
++    const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
++#endif
++    
++    if (png_ptr->interlaced)
++    {
++        if (!(png_ptr->transformations & PNG_INTERLACE))
++            png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
++                                png_pass_ystart[0]) / png_pass_yinc[0];
++        else
++           png_ptr->num_rows = png_ptr->height;
++
++        png_ptr->iwidth = (png_ptr->width +
++                           png_pass_inc[png_ptr->pass] - 1 -
++                           png_pass_start[png_ptr->pass]) /
++                           png_pass_inc[png_ptr->pass];
++    }
++    else
++    {
++        png_ptr->num_rows = png_ptr->height;
++        png_ptr->iwidth = png_ptr->width;
++    }
++    png_ptr->flags &= ~PNG_FLAG_ZLIB_FINISHED;
++    if (inflateReset(&(png_ptr->zstream)) != Z_OK)
++        png_error(png_ptr, "inflateReset failed");
++    png_ptr->zstream.avail_in = 0;
++    png_ptr->zstream.next_in = 0;
++    png_ptr->zstream.next_out = png_ptr->row_buf;
++    png_ptr->zstream.avail_out = (uInt)PNG_ROWBYTES(png_ptr->pixel_depth,
++        png_ptr->iwidth) + 1;
++}
++#endif /* PNG_READ_APNG_SUPPORTED */
+ #endif /* PNG_READ_SUPPORTED */
+diff -Nur libpng-1.2.44.orig/pngset.c libpng-1.2.44/pngset.c
+--- libpng-1.2.44.orig/pngset.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngset.c	2010-07-08 21:21:33.996027603 +0200
+@@ -266,6 +266,11 @@
+       info_ptr->rowbytes = (png_size_t)0;
+    else
+       info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
++
++#ifdef PNG_APNG_SUPPORTED
++   /* for non-animated png. this may be overritten from an acTL chunk later */
++   info_ptr->num_frames = 1;
++#endif
+ }
+ 
+ #ifdef PNG_oFFs_SUPPORTED
+@@ -960,6 +965,142 @@
+ }
+ #endif /* PNG_sPLT_SUPPORTED */
+ 
++#ifdef PNG_APNG_SUPPORTED
++png_uint_32 PNGAPI
++png_set_acTL(png_structp png_ptr, png_infop info_ptr, 
++    png_uint_32 num_frames, png_uint_32 num_plays)
++{
++    png_debug1(1, "in %s storage function", "acTL");
++
++    if (png_ptr == NULL || info_ptr == NULL)
++    {
++        png_warning(png_ptr,
++                    "Call to png_set_acTL() with NULL png_ptr "
++                    "or info_ptr ignored");
++        return (0);
++    }
++    if (num_frames == 0)
++    {
++        png_warning(png_ptr,
++                    "Ignoring attempt to set acTL with num_frames zero");
++        return (0);
++    }
++    if (num_frames > PNG_UINT_31_MAX)
++    {
++        png_warning(png_ptr,
++                    "Ignoring attempt to set acTL with num_frames > 2^31-1");
++        return (0);
++    }
++    if (num_plays > PNG_UINT_31_MAX)
++    {
++        png_warning(png_ptr,
++                    "Ignoring attempt to set acTL with num_plays "
++                    "> 2^31-1");
++        return (0);
++    }
++    
++    info_ptr->num_frames = num_frames;
++    info_ptr->num_plays = num_plays;
++    
++    info_ptr->valid |= PNG_INFO_acTL;
++    
++    return (1);
++}
++
++/* delay_num and delay_den can hold any 16-bit values including zero */
++png_uint_32 PNGAPI
++png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr, 
++    png_uint_32 width, png_uint_32 height,
++    png_uint_32 x_offset, png_uint_32 y_offset,
++    png_uint_16 delay_num, png_uint_16 delay_den,
++    png_byte dispose_op, png_byte blend_op)
++{
++    png_debug1(1, "in %s storage function", "fcTL");
++
++    if (png_ptr == NULL || info_ptr == NULL)
++    {
++        png_warning(png_ptr,
++                    "Call to png_set_fcTL() with NULL png_ptr or info_ptr "
++                    "ignored");
++        return (0);
++    }
++    
++    png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset, 
++                             delay_num, delay_den, dispose_op, blend_op);
++    
++    if (blend_op == PNG_BLEND_OP_OVER)
++    {
++        if (!(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) &&
++            !(png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
++        {
++          png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless "
++                               "and wasteful for opaque images, ignored");
++          blend_op = PNG_BLEND_OP_SOURCE;
++        }
++    }
++
++    info_ptr->next_frame_width = width;
++    info_ptr->next_frame_height = height;
++    info_ptr->next_frame_x_offset = x_offset;
++    info_ptr->next_frame_y_offset = y_offset;
++    info_ptr->next_frame_delay_num = delay_num;
++    info_ptr->next_frame_delay_den = delay_den;
++    info_ptr->next_frame_dispose_op = dispose_op;
++    info_ptr->next_frame_blend_op = blend_op;
++    
++    info_ptr->valid |= PNG_INFO_fcTL;
++    
++    return (1);
++}
++
++void PNGAPI
++png_ensure_fcTL_is_valid(png_structp png_ptr, 
++    png_uint_32 width, png_uint_32 height,
++    png_uint_32 x_offset, png_uint_32 y_offset,
++    png_uint_16 delay_num, png_uint_16 delay_den,
++    png_byte dispose_op, png_byte blend_op)
++{
++    if (width + x_offset > png_ptr->first_frame_width || 
++        height + y_offset > png_ptr->first_frame_height)
++        png_error(png_ptr, "dimensions of a frame are greater than"
++                           "the ones in IHDR");
++    if (width > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid width in fcTL (> 2^31-1)");
++    if (height > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid height in fcTL (> 2^31-1)");
++    if (x_offset > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)");
++    if (y_offset > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)");
++
++    if (dispose_op != PNG_DISPOSE_OP_NONE &&
++        dispose_op != PNG_DISPOSE_OP_BACKGROUND &&
++        dispose_op != PNG_DISPOSE_OP_PREVIOUS)
++        png_error(png_ptr, "invalid dispose_op in fcTL");
++
++    if (blend_op != PNG_BLEND_OP_SOURCE &&
++        blend_op != PNG_BLEND_OP_OVER)
++        png_error(png_ptr, "invalid blend_op in fcTL");
++}
++
++png_uint_32 PNGAPI
++png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr,
++                              png_byte is_hidden)
++{
++    png_debug(1, "in png_first_frame_is_hidden()");
++    
++    if (png_ptr == NULL)
++        return 0;
++    
++    if(is_hidden)
++        png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
++    else
++        png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN;
++    
++    return 1;
++}
++#endif /* PNG_APNG_SUPPORTED */
++
+ #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+ void PNGAPI
+ png_set_unknown_chunks(png_structp png_ptr,
+diff -Nur libpng-1.2.44.orig/pngwrite.c libpng-1.2.44/pngwrite.c
+--- libpng-1.2.44.orig/pngwrite.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngwrite.c	2010-07-08 21:21:33.847089331 +0200
+@@ -57,6 +57,10 @@
+    /* The rest of these check to see if the valid field has the appropriate
+     * flag set, and if it does, writes the chunk.
+     */
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   if (info_ptr->valid & PNG_INFO_acTL)
++      png_write_acTL(png_ptr, info_ptr->num_frames, info_ptr->num_plays);
++#endif
+ #ifdef PNG_WRITE_gAMA_SUPPORTED
+    if (info_ptr->valid & PNG_INFO_gAMA)
+    {
+@@ -319,6 +323,10 @@
+       return;
+    if (!(png_ptr->mode & PNG_HAVE_IDAT))
+       png_error(png_ptr, "No IDATs written into file");
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   if (png_ptr->num_frames_written != png_ptr->num_frames_to_write)
++      png_error(png_ptr, "Not enough frames written");
++#endif
+ 
+    /* See if user wants us to write information chunks */
+    if (info_ptr != NULL)
+@@ -1589,4 +1597,39 @@
+    params = params;
+ }
+ #endif
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++void PNGAPI
++png_write_frame_head(png_structp png_ptr, png_infop info_ptr,
++    png_bytepp row_pointers, png_uint_32 width, png_uint_32 height, 
++    png_uint_32 x_offset, png_uint_32 y_offset, 
++    png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++    png_byte blend_op)
++{
++    png_debug(1, "in png_write_frame_head");
++    
++    /* there is a chance this has been set after png_write_info was called,
++    * so it would be set but not written. is there a way to be sure? */
++    if (!(info_ptr->valid & PNG_INFO_acTL))
++        png_error(png_ptr, "png_write_frame_head(): acTL not set");
++    
++    png_write_reset(png_ptr);
++    
++    png_write_reinit(png_ptr, info_ptr, width, height);
++    
++    if ( !(png_ptr->num_frames_written == 0 && 
++           (png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) ) )
++        png_write_fcTL(png_ptr, width, height, x_offset, y_offset, 
++                       delay_num, delay_den, dispose_op, blend_op);
++}
++
++void PNGAPI
++png_write_frame_tail(png_structp png_ptr, png_infop png_info)
++{
++    png_debug(1, "in png_write_frame_tail");
++    
++    png_ptr->num_frames_written++;
++}
++#endif /* PNG_WRITE_APNG_SUPPORTED */
++
+ #endif /* PNG_WRITE_SUPPORTED */
+diff -Nur libpng-1.2.44.orig/pngwutil.c libpng-1.2.44/pngwutil.c
+--- libpng-1.2.44.orig/pngwutil.c	2010-06-26 02:31:14.000000000 +0200
++++ libpng-1.2.44/pngwutil.c	2010-07-08 21:21:34.095873630 +0200
+@@ -516,6 +516,11 @@
+    /* Write the chunk */
+    png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
+ 
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   png_ptr->first_frame_width = width;
++   png_ptr->first_frame_height = height;
++#endif
++
+    /* Initialize zlib with PNG info */
+    png_ptr->zstream.zalloc = png_zalloc;
+    png_ptr->zstream.zfree = png_zfree;
+@@ -641,6 +646,9 @@
+ {
+ #ifdef PNG_USE_LOCAL_ARRAYS
+    PNG_IDAT;
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   PNG_fdAT;
++#endif
+ #endif
+ 
+    png_debug(1, "in png_write_IDAT");
+@@ -686,7 +694,28 @@
+             "Invalid zlib compression method or flags in IDAT");
+    }
+ 
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   if(png_ptr->num_frames_written == 0)
++#endif
+    png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   else
++   {
++      png_byte buf[4];
++      
++      png_write_chunk_start(png_ptr, (png_bytep)png_fdAT, 4 + length);
++      
++      png_save_uint_32(buf, png_ptr->next_seq_num);
++      png_write_chunk_data(png_ptr, buf, 4);
++      
++      png_write_chunk_data(png_ptr, data, length);
++      
++      png_write_chunk_end(png_ptr);
++      
++      png_ptr->next_seq_num++;
++   }
++#endif
++
+    png_ptr->mode |= PNG_HAVE_IDAT;
+ }
+ 
+@@ -1754,6 +1783,70 @@
+ }
+ #endif
+ 
++#ifdef PNG_WRITE_APNG_SUPPORTED
++void /* PRIVATE */
++png_write_acTL(png_structp png_ptr,
++   png_uint_32 num_frames, png_uint_32 num_plays)
++{
++#ifdef PNG_USE_LOCAL_ARRAYS
++    PNG_acTL;
++#endif
++    png_byte data[16];
++    
++    png_debug(1, "in png_write_acTL");
++    
++    png_ptr->num_frames_to_write = num_frames;
++    
++    if (png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN)
++        num_frames--;
++    
++    png_save_uint_32(data, num_frames);
++    png_save_uint_32(data + 4, num_plays);
++    
++    png_write_chunk(png_ptr, (png_bytep)png_acTL, data, (png_size_t)8);
++}
++
++void /* PRIVATE */
++png_write_fcTL(png_structp png_ptr, png_uint_32 width, png_uint_32 height, 
++    png_uint_32 x_offset, png_uint_32 y_offset,
++    png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op, 
++    png_byte blend_op)
++{
++#ifdef PNG_USE_LOCAL_ARRAYS
++    PNG_fcTL;
++#endif
++    png_byte data[26];
++    
++    png_debug(1, "in png_write_fcTL");
++    
++    if (png_ptr->num_frames_written == 0 && (x_offset != 0 || y_offset != 0))
++        png_error(png_ptr, "x and/or y offset for the first frame aren't 0");
++    if (png_ptr->num_frames_written == 0 && 
++        (width != png_ptr->first_frame_width || 
++         height != png_ptr->first_frame_height))
++        png_error(png_ptr, "width and/or height in the first frame's fcTL "
++                           "don't match the ones in IHDR");
++    
++    /* more error checking */
++    png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset, 
++                             delay_num, delay_den, dispose_op, blend_op);
++    
++    png_save_uint_32(data, png_ptr->next_seq_num);
++    png_save_uint_32(data + 4, width);
++    png_save_uint_32(data + 8, height);
++    png_save_uint_32(data + 12, x_offset);
++    png_save_uint_32(data + 16, y_offset);
++    png_save_uint_16(data + 20, delay_num);
++    png_save_uint_16(data + 22, delay_den);
++    data[24] = dispose_op;
++    data[25] = blend_op;
++    
++    png_write_chunk(png_ptr, (png_bytep)png_fcTL, data, (png_size_t)26);
++    
++    png_ptr->next_seq_num++;
++}
++#endif /* PNG_WRITE_APNG_SUPPORTED */
++
+ /* Initializes the row writing capability of libpng */
+ void /* PRIVATE */
+ png_write_start_row(png_structp png_ptr)
+@@ -2159,8 +2252,8 @@
+ #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+   if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
+   {
+-      /* These will never be selected so we need not test them. */
+-      filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
++      /* These use previous row */
++      filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_AVG | PNG_FILTER_PAETH);
+   }
+ #endif 
+ 
+@@ -2829,4 +2922,39 @@
+    }
+ #endif
+ }
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++void /* PRIVATE */
++png_write_reset(png_structp png_ptr)
++{
++    png_ptr->row_number = 0;
++    png_ptr->pass = 0;
++    png_ptr->mode &= ~PNG_HAVE_IDAT;
++}
++
++void /* PRIVATE */
++png_write_reinit(png_structp png_ptr, png_infop info_ptr, 
++                 png_uint_32 width, png_uint_32 height)
++{
++    if (png_ptr->num_frames_written == 0 && 
++        (width != png_ptr->first_frame_width || 
++         height != png_ptr->first_frame_height))
++        png_error(png_ptr, "width and/or height in the first frame's fcTL "
++                           "don't match the ones in IHDR");
++    if (width > png_ptr->first_frame_width || 
++        height > png_ptr->first_frame_height)
++        png_error(png_ptr, "width and/or height for a frame greater than"
++                           "the ones in IHDR");
++    
++    png_set_IHDR(png_ptr, info_ptr, width, height, 
++                 info_ptr->bit_depth, info_ptr->color_type, 
++                 info_ptr->interlace_type, info_ptr->compression_type,
++                 info_ptr->filter_type);
++   
++    png_ptr->width = width;
++    png_ptr->height = height;
++    png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
++    png_ptr->usr_width = png_ptr->width;
++}
++#endif
+ #endif /* PNG_WRITE_SUPPORTED */