Updated the bundled libpng to v1.5.1 (released Feb 3, 2011).

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@8523 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 381 insertions, 254 deletions

diff --git a/png/pngpread.c b/png/pngpread.c
index 7adb7b854..7b1149bab 100644
--- a/png/pngpread.c
+++ b/png/pngpread.c
@@ -1,8 +1,8 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.2.38 [July 16, 2009]
- * Copyright (c) 1998-2009 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Copyright (c) 1998-2011 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.)
  *
@@ -11,8 +11,8 @@
  * and license in png.h
  */
 
-#define PNG_INTERNAL
-#include "png.h"
+#include "pngpriv.h"
+
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 
 /* Push model modes */
@@ -28,7 +28,7 @@
 
 void PNGAPI
 png_process_data(png_structp png_ptr, png_infop info_ptr,
-   png_bytep buffer, png_size_t buffer_size)
+    png_bytep buffer, png_size_t buffer_size)
 {
    if (png_ptr == NULL || info_ptr == NULL)
       return;
@@ -41,6 +41,64 @@ png_process_data(png_structp png_ptr, png_infop info_ptr,
    }
 }
 
+png_size_t PNGAPI
+png_process_data_pause(png_structp png_ptr, int save)
+{
+   if (png_ptr != NULL)
+   {
+      /* It's easiest for the caller if we do the save, then the caller doesn't
+       * have to supply the same data again:
+       */
+      if (save)
+         png_push_save_buffer(png_ptr);
+      else
+      {
+         /* This includes any pending saved bytes: */
+         png_size_t remaining = png_ptr->buffer_size;
+         png_ptr->buffer_size = 0;
+
+         /* So subtract the saved buffer size, unless all the data
+          * is actually 'saved', in which case we just return 0
+          */
+         if (png_ptr->save_buffer_size < remaining)
+            return remaining - png_ptr->save_buffer_size;
+      }
+   }
+
+   return 0;
+}
+
+png_uint_32 PNGAPI
+png_process_data_skip(png_structp png_ptr)
+{
+   png_uint_32 remaining = 0;
+
+   if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE &&
+      png_ptr->skip_length > 0)
+   {
+      /* At the end of png_process_data the buffer size must be 0 (see the loop
+       * above) so we can detect a broken call here:
+       */
+      if (png_ptr->buffer_size != 0)
+         png_error(png_ptr,
+            "png_process_data_skip called inside png_process_data");
+
+      /* If is impossible for there to be a saved buffer at this point -
+       * otherwise we could not be in SKIP mode.  This will also happen if
+       * png_process_skip is called inside png_process_data (but only very
+       * rarely.)
+       */
+      if (png_ptr->save_buffer_size != 0)
+         png_error(png_ptr, "png_process_data_skip called with saved data");
+
+      remaining = png_ptr->skip_length;
+      png_ptr->skip_length = 0;
+      png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+   }
+
+   return remaining;
+}
+
 /* What we do with the incoming data depends on what we were previously
  * doing before we ran out of data...
  */
@@ -70,7 +128,7 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
          break;
       }
 
-#if defined(PNG_READ_tEXt_SUPPORTED)
+#ifdef PNG_READ_tEXt_SUPPORTED
       case PNG_READ_tEXt_MODE:
       {
          png_push_read_tEXt(png_ptr, info_ptr);
@@ -78,7 +136,7 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
       }
 
 #endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
+#ifdef PNG_READ_zTXt_SUPPORTED
       case PNG_READ_zTXt_MODE:
       {
          png_push_read_zTXt(png_ptr, info_ptr);
@@ -86,7 +144,7 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
       }
 
 #endif
-#if defined(PNG_READ_iTXt_SUPPORTED)
+#ifdef PNG_READ_iTXt_SUPPORTED
       case PNG_READ_iTXt_MODE:
       {
          png_push_read_iTXt(png_ptr, info_ptr);
@@ -126,7 +184,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
    }
 
    png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
-      num_to_check);
+       num_to_check);
    png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
 
    if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
@@ -134,6 +192,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
       if (num_checked < 4 &&
           png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
          png_error(png_ptr, "Not a PNG file");
+
       else
          png_error(png_ptr, "PNG file corrupted by ASCII conversion");
    }
@@ -149,63 +208,62 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
 void /* PRIVATE */
 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 {
-#ifdef PNG_USE_LOCAL_ARRAYS
-      PNG_CONST PNG_IHDR;
-      PNG_CONST PNG_IDAT;
-      PNG_CONST PNG_IEND;
-      PNG_CONST PNG_PLTE;
-#if defined(PNG_READ_bKGD_SUPPORTED)
-      PNG_CONST PNG_bKGD;
+      PNG_IHDR;
+      PNG_IDAT;
+      PNG_IEND;
+      PNG_PLTE;
+#ifdef PNG_READ_bKGD_SUPPORTED
+      PNG_bKGD;
 #endif
-#if defined(PNG_READ_cHRM_SUPPORTED)
-      PNG_CONST PNG_cHRM;
+#ifdef PNG_READ_cHRM_SUPPORTED
+      PNG_cHRM;
 #endif
-#if defined(PNG_READ_gAMA_SUPPORTED)
-      PNG_CONST PNG_gAMA;
+#ifdef PNG_READ_gAMA_SUPPORTED
+      PNG_gAMA;
 #endif
-#if defined(PNG_READ_hIST_SUPPORTED)
-      PNG_CONST PNG_hIST;
+#ifdef PNG_READ_hIST_SUPPORTED
+      PNG_hIST;
 #endif
-#if defined(PNG_READ_iCCP_SUPPORTED)
-      PNG_CONST PNG_iCCP;
+#ifdef PNG_READ_iCCP_SUPPORTED
+      PNG_iCCP;
 #endif
-#if defined(PNG_READ_iTXt_SUPPORTED)
-      PNG_CONST PNG_iTXt;
+#ifdef PNG_READ_iTXt_SUPPORTED
+      PNG_iTXt;
 #endif
-#if defined(PNG_READ_oFFs_SUPPORTED)
-      PNG_CONST PNG_oFFs;
+#ifdef PNG_READ_oFFs_SUPPORTED
+      PNG_oFFs;
 #endif
-#if defined(PNG_READ_pCAL_SUPPORTED)
-      PNG_CONST PNG_pCAL;
+#ifdef PNG_READ_pCAL_SUPPORTED
+      PNG_pCAL;
 #endif
-#if defined(PNG_READ_pHYs_SUPPORTED)
-      PNG_CONST PNG_pHYs;
+#ifdef PNG_READ_pHYs_SUPPORTED
+      PNG_pHYs;
 #endif
-#if defined(PNG_READ_sBIT_SUPPORTED)
-      PNG_CONST PNG_sBIT;
+#ifdef PNG_READ_sBIT_SUPPORTED
+      PNG_sBIT;
 #endif
-#if defined(PNG_READ_sCAL_SUPPORTED)
-      PNG_CONST PNG_sCAL;
+#ifdef PNG_READ_sCAL_SUPPORTED
+      PNG_sCAL;
 #endif
-#if defined(PNG_READ_sRGB_SUPPORTED)
-      PNG_CONST PNG_sRGB;
+#ifdef PNG_READ_sRGB_SUPPORTED
+      PNG_sRGB;
 #endif
-#if defined(PNG_READ_sPLT_SUPPORTED)
-      PNG_CONST PNG_sPLT;
+#ifdef PNG_READ_sPLT_SUPPORTED
+      PNG_sPLT;
 #endif
-#if defined(PNG_READ_tEXt_SUPPORTED)
-      PNG_CONST PNG_tEXt;
+#ifdef PNG_READ_tEXt_SUPPORTED
+      PNG_tEXt;
 #endif
-#if defined(PNG_READ_tIME_SUPPORTED)
-      PNG_CONST PNG_tIME;
+#ifdef PNG_READ_tIME_SUPPORTED
+      PNG_tIME;
 #endif
-#if defined(PNG_READ_tRNS_SUPPORTED)
-      PNG_CONST PNG_tRNS;
+#ifdef PNG_READ_tRNS_SUPPORTED
+      PNG_tRNS;
 #endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
-      PNG_CONST PNG_zTXt;
+#ifdef PNG_READ_zTXt_SUPPORTED
+      PNG_zTXt;
 #endif
-#endif /* PNG_USE_LOCAL_ARRAYS */
+
    /* First we make sure we have enough data for the 4 byte chunk name
     * and the 4 byte chunk length before proceeding with decoding the
     * chunk data.  To fully decode each of these chunks, we also make
@@ -231,8 +289,8 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
    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;
+      if (png_ptr->mode & PNG_AFTER_IDAT)
+         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
    if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
    {
@@ -285,7 +343,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
             png_error(png_ptr, "Missing IHDR before IDAT");
 
          else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-                  !(png_ptr->mode & PNG_HAVE_PLTE))
+             !(png_ptr->mode & PNG_HAVE_PLTE))
             png_error(png_ptr, "Missing PLTE before IDAT");
       }
    }
@@ -322,19 +380,21 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
                return;
 
          if (png_ptr->mode & PNG_AFTER_IDAT)
-            png_error(png_ptr, "Too many IDAT's found");
+            png_benign_error(png_ptr, "Too many IDATs found");
       }
 
       png_ptr->idat_size = png_ptr->push_length;
       png_ptr->mode |= PNG_HAVE_IDAT;
       png_ptr->process_mode = PNG_READ_IDAT_MODE;
       png_push_have_info(png_ptr, info_ptr);
-      png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
+      png_ptr->zstream.avail_out =
+          (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+          png_ptr->iwidth) + 1;
       png_ptr->zstream.next_out = png_ptr->row_buf;
       return;
    }
 
-#if defined(PNG_READ_gAMA_SUPPORTED)
+#ifdef PNG_READ_gAMA_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -347,7 +407,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_sBIT_SUPPORTED)
+#ifdef PNG_READ_sBIT_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -360,7 +420,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_cHRM_SUPPORTED)
+#ifdef PNG_READ_cHRM_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -373,7 +433,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_sRGB_SUPPORTED)
+#ifdef PNG_READ_sRGB_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -386,7 +446,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_iCCP_SUPPORTED)
+#ifdef PNG_READ_iCCP_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -399,7 +459,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_sPLT_SUPPORTED)
+#ifdef PNG_READ_sPLT_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -412,7 +472,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_tRNS_SUPPORTED)
+#ifdef PNG_READ_tRNS_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -425,7 +485,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_bKGD_SUPPORTED)
+#ifdef PNG_READ_bKGD_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -438,7 +498,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_hIST_SUPPORTED)
+#ifdef PNG_READ_hIST_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -451,7 +511,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_pHYs_SUPPORTED)
+#ifdef PNG_READ_pHYs_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -464,7 +524,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_oFFs_SUPPORTED)
+#ifdef PNG_READ_oFFs_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -477,7 +537,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 #endif
 
-#if defined(PNG_READ_pCAL_SUPPORTED)
+#ifdef PNG_READ_pCAL_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -490,7 +550,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_sCAL_SUPPORTED)
+#ifdef PNG_READ_sCAL_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -503,7 +563,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_tIME_SUPPORTED)
+#ifdef PNG_READ_tIME_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -516,7 +576,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_tEXt_SUPPORTED)
+#ifdef PNG_READ_tEXt_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -529,7 +589,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_zTXt_SUPPORTED)
+#ifdef PNG_READ_zTXt_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -542,7 +602,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #endif
-#if defined(PNG_READ_iTXt_SUPPORTED)
+#ifdef PNG_READ_iTXt_SUPPORTED
    else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -580,32 +640,45 @@ png_push_crc_finish(png_structp png_ptr)
 {
    if (png_ptr->skip_length && png_ptr->save_buffer_size)
    {
-      png_size_t save_size;
+      png_size_t save_size = png_ptr->save_buffer_size;
+      png_uint_32 skip_length = png_ptr->skip_length;
+
+      /* We want the smaller of 'skip_length' and 'save_buffer_size', but
+       * they are of different types and we don't know which variable has the
+       * fewest bits.  Carefully select the smaller and cast it to the type of
+       * the larger - this cannot overflow.  Do not cast in the following test
+       * - it will break on either 16 or 64 bit platforms.
+       */
+      if (skip_length < save_size)
+         save_size = (png_size_t)skip_length;
 
-      if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
-         save_size = (png_size_t)png_ptr->skip_length;
       else
-         save_size = png_ptr->save_buffer_size;
+         skip_length = (png_uint_32)save_size;
 
       png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
 
-      png_ptr->skip_length -= save_size;
+      png_ptr->skip_length -= skip_length;
       png_ptr->buffer_size -= save_size;
       png_ptr->save_buffer_size -= save_size;
       png_ptr->save_buffer_ptr += save_size;
    }
    if (png_ptr->skip_length && png_ptr->current_buffer_size)
    {
-      png_size_t save_size;
+      png_size_t save_size = png_ptr->current_buffer_size;
+      png_uint_32 skip_length = png_ptr->skip_length;
+
+      /* We want the smaller of 'skip_length' and 'current_buffer_size', here,
+       * the same problem exists as above and the same solution.
+       */
+      if (skip_length < save_size)
+         save_size = (png_size_t)skip_length;
 
-      if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
-         save_size = (png_size_t)png_ptr->skip_length;
       else
-         save_size = png_ptr->current_buffer_size;
+         skip_length = (png_uint_32)save_size;
 
       png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
 
-      png_ptr->skip_length -= save_size;
+      png_ptr->skip_length -= skip_length;
       png_ptr->buffer_size -= save_size;
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
@@ -623,7 +696,7 @@ png_push_crc_finish(png_structp png_ptr)
    }
 }
 
-void PNGAPI
+void PNGCBAPI
 png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
 {
    png_bytep ptr;
@@ -638,6 +711,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
 
       if (length < png_ptr->save_buffer_size)
          save_size = length;
+
       else
          save_size = png_ptr->save_buffer_size;
 
@@ -678,28 +752,35 @@ png_push_save_buffer(png_structp png_ptr)
 
          istop = png_ptr->save_buffer_size;
          for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
-            i < istop; i++, sp++, dp++)
+             i < istop; i++, sp++, dp++)
          {
             *dp = *sp;
          }
       }
    }
    if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
-      png_ptr->save_buffer_max)
+       png_ptr->save_buffer_max)
    {
       png_size_t new_max;
       png_bytep old_buffer;
 
       if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
-         (png_ptr->current_buffer_size + 256))
+          (png_ptr->current_buffer_size + 256))
       {
-        png_error(png_ptr, "Potential overflow of save_buffer");
+         png_error(png_ptr, "Potential overflow of save_buffer");
       }
 
       new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
       old_buffer = png_ptr->save_buffer;
-      png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
-         (png_uint_32)new_max);
+      png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
+          (png_size_t)new_max);
+
+      if (png_ptr->save_buffer == NULL)
+      {
+         png_free(png_ptr, old_buffer);
+         png_error(png_ptr, "Insufficient memory for save_buffer");
+      }
+
       png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
       png_free(png_ptr, old_buffer);
       png_ptr->save_buffer_max = new_max;
@@ -728,9 +809,7 @@ png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
 void /* PRIVATE */
 png_push_read_IDAT(png_structp png_ptr)
 {
-#ifdef PNG_USE_LOCAL_ARRAYS
-   PNG_CONST PNG_IDAT;
-#endif
+   PNG_IDAT;
    if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
    {
       png_byte chunk_length[4];
@@ -750,8 +829,10 @@ png_push_read_IDAT(png_structp png_ptr)
       if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
       {
          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+
          if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
             png_error(png_ptr, "Not enough compressed data");
+
          return;
       }
 
@@ -759,49 +840,52 @@ png_push_read_IDAT(png_structp png_ptr)
    }
    if (png_ptr->idat_size && png_ptr->save_buffer_size)
    {
-      png_size_t save_size;
-
-      if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
-      {
-         save_size = (png_size_t)png_ptr->idat_size;
+      png_size_t save_size = png_ptr->save_buffer_size;
+      png_uint_32 idat_size = png_ptr->idat_size;
+
+      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+       * are of different types and we don't know which variable has the fewest
+       * bits.  Carefully select the smaller and cast it to the type of the
+       * larger - this cannot overflow.  Do not cast in the following test - it
+       * will break on either 16 or 64 bit platforms.
+       */
+      if (idat_size < save_size)
+         save_size = (png_size_t)idat_size;
 
-         /* Check for overflow */
-         if ((png_uint_32)save_size != png_ptr->idat_size)
-            png_error(png_ptr, "save_size overflowed in pngpread");
-      }
       else
-         save_size = png_ptr->save_buffer_size;
+         idat_size = (png_uint_32)save_size;
 
       png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
 
-      if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
-         png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
+      png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
 
-      png_ptr->idat_size -= save_size;
+      png_ptr->idat_size -= idat_size;
       png_ptr->buffer_size -= save_size;
       png_ptr->save_buffer_size -= save_size;
       png_ptr->save_buffer_ptr += save_size;
    }
+
    if (png_ptr->idat_size && png_ptr->current_buffer_size)
    {
-      png_size_t save_size;
+      png_size_t save_size = png_ptr->current_buffer_size;
+      png_uint_32 idat_size = png_ptr->idat_size;
 
-      if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
-      {
-         save_size = (png_size_t)png_ptr->idat_size;
+      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+       * are of different types and we don't know which variable has the fewest
+       * bits.  Carefully select the smaller and cast it to the type of the
+       * larger - this cannot overflow.
+       */
+      if (idat_size < save_size)
+         save_size = (png_size_t)idat_size;
 
-         /* Check for overflow */
-         if ((png_uint_32)save_size != png_ptr->idat_size)
-            png_error(png_ptr, "save_size overflowed in pngpread");
-      }
       else
-         save_size = png_ptr->current_buffer_size;
+         idat_size = (png_uint_32)save_size;
 
       png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
-      if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
-        png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
 
-      png_ptr->idat_size -= save_size;
+      png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+      png_ptr->idat_size -= idat_size;
       png_ptr->buffer_size -= save_size;
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
@@ -824,60 +908,104 @@ void /* PRIVATE */
 png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
    png_size_t buffer_length)
 {
-   int ret;
-
-   if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
-      png_error(png_ptr, "Extra compression data");
+   /* The caller checks for a non-zero buffer length. */
+   if (!(buffer_length > 0) || buffer == NULL)
+      png_error(png_ptr, "No IDAT data (internal error)");
 
+   /* This routine must process all the data it has been given
+    * before returning, calling the row callback as required to
+    * handle the uncompressed results.
+    */
    png_ptr->zstream.next_in = buffer;
    png_ptr->zstream.avail_in = (uInt)buffer_length;
-   for (;;)
+
+   /* Keep going until the decompressed data is all processed
+    * or the stream marked as finished.
+    */
+   while (png_ptr->zstream.avail_in > 0 &&
+          !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
    {
-      ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
-      if (ret != Z_OK)
+      int ret;
+
+      /* We have data for zlib, but we must check that zlib
+       * has someplace to put the results.  It doesn't matter
+       * if we don't expect any results -- it may be the input
+       * data is just the LZ end code.
+       */
+      if (!(png_ptr->zstream.avail_out > 0))
       {
-         if (ret == Z_STREAM_END)
-         {
-            if (png_ptr->zstream.avail_in)
-               png_error(png_ptr, "Extra compressed data");
+         png_ptr->zstream.avail_out =
+             (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+             png_ptr->iwidth) + 1;
 
-            if (!(png_ptr->zstream.avail_out))
-            {
-               png_push_process_row(png_ptr);
-            }
+         png_ptr->zstream.next_out = png_ptr->row_buf;
+      }
 
-            png_ptr->mode |= PNG_AFTER_IDAT;
-            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
-            break;
-         }
-         else if (ret == Z_BUF_ERROR)
-            break;
+      /* Using Z_SYNC_FLUSH here means that an unterminated
+       * LZ stream (a stream with a missing end code) can still
+       * be handled, otherwise (Z_NO_FLUSH) a future zlib
+       * implementation might defer output and therefore
+       * change the current behavior (see comments in inflate.c
+       * for why this doesn't happen at present with zlib 1.2.5).
+       */
+      ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
+
+      /* Check for any failure before proceeding. */
+      if (ret != Z_OK && ret != Z_STREAM_END)
+      {
+         /* Terminate the decompression. */
+         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+
+         /* This may be a truncated stream (missing or
+          * damaged end code).  Treat that as a warning.
+          */
+         if (png_ptr->row_number >= png_ptr->num_rows ||
+             png_ptr->pass > 6)
+            png_warning(png_ptr, "Truncated compressed data in IDAT");
 
          else
-            png_error(png_ptr, "Decompression Error");
+            png_error(png_ptr, "Decompression error in IDAT");
+
+         /* Skip the check on unprocessed input */
+         return;
       }
-      if (!(png_ptr->zstream.avail_out))
+
+      /* Did inflate output any data? */
+      if (png_ptr->zstream.next_out != png_ptr->row_buf)
       {
-         if ((
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
-             png_ptr->interlaced && png_ptr->pass > 6) ||
-             (!png_ptr->interlaced &&
-#endif
-             png_ptr->row_number == png_ptr->num_rows))
+         /* Is this unexpected data after the last row?
+          * If it is, artificially terminate the LZ output
+          * here.
+          */
+         if (png_ptr->row_number >= png_ptr->num_rows ||
+             png_ptr->pass > 6)
          {
-           if (png_ptr->zstream.avail_in)
-             png_warning(png_ptr, "Too much data in IDAT chunks");
-           png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
-           break;
+            /* Extra data. */
+            png_warning(png_ptr, "Extra compressed data in IDAT");
+            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+
+            /* Do no more processing; skip the unprocessed
+             * input check below.
+             */
+            return;
          }
-         png_push_process_row(png_ptr);
-         png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
-         png_ptr->zstream.next_out = png_ptr->row_buf;
+
+         /* Do we have a complete row? */
+         if (png_ptr->zstream.avail_out == 0)
+            png_push_process_row(png_ptr);
       }
 
-      else
-         break;
+      /* And check for the end of the stream. */
+      if (ret == Z_STREAM_END)
+         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
    }
+
+   /* All the data should have been processed, if anything
+    * is left at this point we have bytes of IDAT data
+    * after the zlib end code.
+    */
+   if (png_ptr->zstream.avail_in > 0)
+      png_warning(png_ptr, "Extra compression data in IDAT");
 }
 
 void /* PRIVATE */
@@ -893,23 +1021,22 @@ png_push_process_row(png_structp png_ptr)
        png_ptr->row_info.width);
 
    png_read_filter_row(png_ptr, &(png_ptr->row_info),
-      png_ptr->row_buf + 1, png_ptr->prev_row + 1,
-      (int)(png_ptr->row_buf[0]));
+       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
+       (int)(png_ptr->row_buf[0]));
 
-   png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
-      png_ptr->rowbytes + 1);
+   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
 
    if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
       png_do_read_transformations(png_ptr);
 
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Blow up interlaced rows to full size */
    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
    {
       if (png_ptr->pass < 6)
 /*       old interface (pre-1.0.9):
          png_do_read_interlace(&(png_ptr->row_info),
-            png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
+             png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
  */
          png_do_read_interlace(png_ptr);
 
@@ -928,7 +1055,7 @@ png_push_process_row(png_structp png_ptr)
             {
                for (i = 0; i < 4 && png_ptr->pass == 2; i++)
                {
-                  png_push_have_row(png_ptr, png_bytep_NULL);
+                  png_push_have_row(png_ptr, NULL);
                   png_read_push_finish_row(png_ptr);
                }
             }
@@ -937,14 +1064,14 @@ png_push_process_row(png_structp png_ptr)
             {
                for (i = 0; i < 2 && png_ptr->pass == 4; i++)
                {
-                  png_push_have_row(png_ptr, png_bytep_NULL);
+                  png_push_have_row(png_ptr, NULL);
                   png_read_push_finish_row(png_ptr);
                }
             }
 
             if (png_ptr->pass == 6 && png_ptr->height <= 4)
             {
-                png_push_have_row(png_ptr, png_bytep_NULL);
+                png_push_have_row(png_ptr, NULL);
                 png_read_push_finish_row(png_ptr);
             }
 
@@ -964,7 +1091,7 @@ png_push_process_row(png_structp png_ptr)
             {
                for (i = 0; i < 4 && png_ptr->pass == 2; i++)
                {
-                  png_push_have_row(png_ptr, png_bytep_NULL);
+                  png_push_have_row(png_ptr, NULL);
                   png_read_push_finish_row(png_ptr);
                }
             }
@@ -984,7 +1111,7 @@ png_push_process_row(png_structp png_ptr)
 
             for (i = 0; i < 4 && png_ptr->pass == 2; i++)
             {
-               png_push_have_row(png_ptr, png_bytep_NULL);
+               png_push_have_row(png_ptr, NULL);
                png_read_push_finish_row(png_ptr);
             }
 
@@ -992,7 +1119,7 @@ png_push_process_row(png_structp png_ptr)
             {
                for (i = 0; i < 2 && png_ptr->pass == 4; i++)
                {
-                  png_push_have_row(png_ptr, png_bytep_NULL);
+                  png_push_have_row(png_ptr, NULL);
                   png_read_push_finish_row(png_ptr);
                }
             }
@@ -1014,7 +1141,7 @@ png_push_process_row(png_structp png_ptr)
             {
                for (i = 0; i < 2 && png_ptr->pass == 4; i++)
                {
-                  png_push_have_row(png_ptr, png_bytep_NULL);
+                  png_push_have_row(png_ptr, NULL);
                   png_read_push_finish_row(png_ptr);
                }
             }
@@ -1034,13 +1161,13 @@ png_push_process_row(png_structp png_ptr)
 
             for (i = 0; i < 2 && png_ptr->pass == 4; i++)
             {
-               png_push_have_row(png_ptr, png_bytep_NULL);
+               png_push_have_row(png_ptr, NULL);
                png_read_push_finish_row(png_ptr);
             }
 
             if (png_ptr->pass == 6) /* Pass 5 might be empty */
             {
-               png_push_have_row(png_ptr, png_bytep_NULL);
+               png_push_have_row(png_ptr, NULL);
                png_read_push_finish_row(png_ptr);
             }
 
@@ -1059,12 +1186,14 @@ png_push_process_row(png_structp png_ptr)
 
             if (png_ptr->pass == 6) /* Skip top generated row */
             {
-               png_push_have_row(png_ptr, png_bytep_NULL);
+               png_push_have_row(png_ptr, NULL);
                png_read_push_finish_row(png_ptr);
             }
 
             break;
          }
+
+         default:
          case 6:
          {
             png_push_have_row(png_ptr, png_ptr->row_buf + 1);
@@ -1073,7 +1202,7 @@ png_push_process_row(png_structp png_ptr)
             if (png_ptr->pass != 6)
                break;
 
-            png_push_have_row(png_ptr, png_bytep_NULL);
+            png_push_have_row(png_ptr, NULL);
             png_read_push_finish_row(png_ptr);
          }
       }
@@ -1089,7 +1218,6 @@ png_push_process_row(png_structp png_ptr)
 void /* PRIVATE */
 png_read_push_finish_row(png_structp png_ptr)
 {
-#ifdef PNG_USE_LOCAL_ARRAYS
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
@@ -1108,25 +1236,24 @@ png_read_push_finish_row(png_structp png_ptr)
     * it, uncomment it here and in png.h
    PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
    */
-#endif
 
    png_ptr->row_number++;
    if (png_ptr->row_number < png_ptr->num_rows)
       return;
 
-#if defined(PNG_READ_INTERLACING_SUPPORTED)
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
-      png_memset_check(png_ptr, png_ptr->prev_row, 0,
-         png_ptr->rowbytes + 1);
+      png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
       do
       {
          png_ptr->pass++;
          if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
              (png_ptr->pass == 3 && png_ptr->width < 3) ||
              (png_ptr->pass == 5 && png_ptr->width < 2))
-           png_ptr->pass++;
+            png_ptr->pass++;
 
          if (png_ptr->pass > 7)
             png_ptr->pass--;
@@ -1135,35 +1262,33 @@ png_read_push_finish_row(png_structp png_ptr)
             break;
 
          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];
-
-         png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
-            png_ptr->iwidth) + 1;
+             png_pass_inc[png_ptr->pass] - 1 -
+             png_pass_start[png_ptr->pass]) /
+             png_pass_inc[png_ptr->pass];
 
          if (png_ptr->transformations & PNG_INTERLACE)
             break;
 
          png_ptr->num_rows = (png_ptr->height +
-            png_pass_yinc[png_ptr->pass] - 1 -
-            png_pass_ystart[png_ptr->pass]) /
-            png_pass_yinc[png_ptr->pass];
+             png_pass_yinc[png_ptr->pass] - 1 -
+             png_pass_ystart[png_ptr->pass]) /
+             png_pass_yinc[png_ptr->pass];
 
       } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
    }
 #endif /* PNG_READ_INTERLACING_SUPPORTED */
 }
 
-#if defined(PNG_READ_tEXt_SUPPORTED)
+#ifdef PNG_READ_tEXt_SUPPORTED
 void /* PRIVATE */
 png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
-   length)
+    length)
 {
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
       {
+         PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
          png_error(png_ptr, "Out of place tEXt");
-         info_ptr = info_ptr; /* To quiet some compiler warnings */
+         /*NOT REACHED*/
       }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1178,7 +1303,7 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-      (png_uint_32)(length + 1));
+       (png_size_t)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
@@ -1218,7 +1343,7 @@ png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
 
       png_push_crc_finish(png_ptr);
 
-#if defined(PNG_MAX_MALLOC_64K)
+#ifdef PNG_MAX_MALLOC_64K
       if (png_ptr->skip_length)
          return;
 #endif
@@ -1231,14 +1356,12 @@ png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
       if (text < key + png_ptr->current_text_size)
          text++;
 
-      text_ptr = (png_textp)png_malloc(png_ptr,
-         (png_uint_32)png_sizeof(png_text));
+      text_ptr = (png_textp)png_malloc(png_ptr, png_sizeof(png_text));
       text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
       text_ptr->key = key;
-#ifdef PNG_iTXt_SUPPORTED
+      text_ptr->itxt_length = 0;
       text_ptr->lang = NULL;
       text_ptr->lang_key = NULL;
-#endif
       text_ptr->text = text;
 
       ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
@@ -1248,21 +1371,22 @@ png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
       png_ptr->current_text = NULL;
 
       if (ret)
-        png_warning(png_ptr, "Insufficient memory to store text chunk.");
+         png_warning(png_ptr, "Insufficient memory to store text chunk");
    }
 }
 #endif
 
-#if defined(PNG_READ_zTXt_SUPPORTED)
+#ifdef PNG_READ_zTXt_SUPPORTED
 void /* PRIVATE */
 png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    length)
 {
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
-      {
-         png_error(png_ptr, "Out of place zTXt");
-         info_ptr = info_ptr; /* To quiet some compiler warnings */
-      }
+   {
+      PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
+      png_error(png_ptr, "Out of place zTXt");
+      /*NOT REACHED*/
+   }
 
 #ifdef PNG_MAX_MALLOC_64K
    /* We can't handle zTXt chunks > 64K, since we don't have enough space
@@ -1278,7 +1402,7 @@ png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-      (png_uint_32)(length + 1));
+       (png_size_t)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
@@ -1343,9 +1467,9 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
 
       text++;
 
-      png_ptr->zstream.next_in = (png_bytep )text;
+      png_ptr->zstream.next_in = (png_bytep)text;
       png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
-         (text - key));
+          (text - key));
       png_ptr->zstream.next_out = png_ptr->zbuf;
       png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
 
@@ -1366,42 +1490,45 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
             png_free(png_ptr, text);
             return;
          }
+
          if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
          {
             if (text == NULL)
             {
                text = (png_charp)png_malloc(png_ptr,
-                     (png_uint_32)(png_ptr->zbuf_size
-                     - png_ptr->zstream.avail_out + key_size + 1));
+                   (png_ptr->zbuf_size
+                   - png_ptr->zstream.avail_out + key_size + 1));
 
                png_memcpy(text + key_size, png_ptr->zbuf,
-                  png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+                   png_ptr->zbuf_size - png_ptr->zstream.avail_out);
 
                png_memcpy(text, key, key_size);
 
                text_size = key_size + png_ptr->zbuf_size -
-                  png_ptr->zstream.avail_out;
+                   png_ptr->zstream.avail_out;
 
                *(text + text_size) = '\0';
             }
+
             else
             {
                png_charp tmp;
 
                tmp = text;
                text = (png_charp)png_malloc(png_ptr, text_size +
-                  (png_uint_32)(png_ptr->zbuf_size 
-                  - png_ptr->zstream.avail_out + 1));
+                   (png_ptr->zbuf_size
+                   - png_ptr->zstream.avail_out + 1));
 
                png_memcpy(text, tmp, text_size);
                png_free(png_ptr, tmp);
 
                png_memcpy(text + text_size, png_ptr->zbuf,
-                  png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+                   png_ptr->zbuf_size - png_ptr->zstream.avail_out);
 
                text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
                *(text + text_size) = '\0';
             }
+
             if (ret != Z_STREAM_END)
             {
                png_ptr->zstream.next_out = png_ptr->zbuf;
@@ -1434,13 +1561,12 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
       text += key_size;
 
       text_ptr = (png_textp)png_malloc(png_ptr,
-          (png_uint_32)png_sizeof(png_text));
+          png_sizeof(png_text));
       text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
       text_ptr->key = key;
-#ifdef PNG_iTXt_SUPPORTED
+      text_ptr->itxt_length = 0;
       text_ptr->lang = NULL;
       text_ptr->lang_key = NULL;
-#endif
       text_ptr->text = text;
 
       ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
@@ -1449,21 +1575,22 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
       png_free(png_ptr, text_ptr);
 
       if (ret)
-        png_warning(png_ptr, "Insufficient memory to store text chunk.");
+         png_warning(png_ptr, "Insufficient memory to store text chunk");
    }
 }
 #endif
 
-#if defined(PNG_READ_iTXt_SUPPORTED)
+#ifdef PNG_READ_iTXt_SUPPORTED
 void /* PRIVATE */
 png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
-   length)
+    length)
 {
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
-      {
-         png_error(png_ptr, "Out of place iTXt");
-         info_ptr = info_ptr; /* To quiet some compiler warnings */
-      }
+   {
+      PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
+      png_error(png_ptr, "Out of place iTXt");
+      /*NOT REACHED*/
+   }
 
 #ifdef PNG_MAX_MALLOC_64K
    png_ptr->skip_length = 0;  /* This may not be necessary */
@@ -1477,7 +1604,7 @@ png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-      (png_uint_32)(length + 1));
+       (png_size_t)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
@@ -1503,6 +1630,7 @@ png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
       png_ptr->current_text_left -= text_size;
       png_ptr->current_text_ptr += text_size;
    }
+
    if (!(png_ptr->current_text_left))
    {
       png_textp text_ptr;
@@ -1521,7 +1649,7 @@ png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
 
       png_push_crc_finish(png_ptr);
 
-#if defined(PNG_MAX_MALLOC_64K)
+#ifdef PNG_MAX_MALLOC_64K
       if (png_ptr->skip_length)
          return;
 #endif
@@ -1546,15 +1674,15 @@ png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
 
       if (lang_key < key + png_ptr->current_text_size - 1)
       {
-        for (; *text; text++)
-           /* Empty loop */ ;
+         for (; *text; text++)
+            /* Empty loop */ ;
       }
 
       if (text < key + png_ptr->current_text_size)
          text++;
 
       text_ptr = (png_textp)png_malloc(png_ptr,
-         (png_uint_32)png_sizeof(png_text));
+          png_sizeof(png_text));
 
       text_ptr->compression = comp_flag + 2;
       text_ptr->key = key;
@@ -1570,7 +1698,7 @@ png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
 
       png_free(png_ptr, text_ptr);
       if (ret)
-        png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
+         png_warning(png_ptr, "Insufficient memory to store iTXt chunk");
    }
 }
 #endif
@@ -1581,41 +1709,41 @@ png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
  */
 void /* PRIVATE */
 png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
-   length)
+    length)
 {
    png_uint_32 skip = 0;
 
    if (!(png_ptr->chunk_name[0] & 0x20))
    {
-#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
       if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
-         PNG_HANDLE_CHUNK_ALWAYS
-#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
-         && png_ptr->read_user_chunk_fn == NULL
+          PNG_HANDLE_CHUNK_ALWAYS
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+          && png_ptr->read_user_chunk_fn == NULL
 #endif
-         )
+          )
 #endif
          png_chunk_error(png_ptr, "unknown critical chunk");
 
-      info_ptr = info_ptr; /* To quiet some compiler warnings */
+      PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
    }
 
-#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
    if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
    {
 #ifdef PNG_MAX_MALLOC_64K
       if (length > (png_uint_32)65535L)
       {
-          png_warning(png_ptr, "unknown chunk too large to fit in memory");
-          skip = length - (png_uint_32)65535L;
-          length = (png_uint_32)65535L;
+         png_warning(png_ptr, "unknown chunk too large to fit in memory");
+         skip = length - (png_uint_32)65535L;
+         length = (png_uint_32)65535L;
       }
 #endif
       png_memcpy((png_charp)png_ptr->unknown_chunk.name,
-                 (png_charp)png_ptr->chunk_name, 
-                 png_sizeof(png_ptr->unknown_chunk.name));
+          (png_charp)png_ptr->chunk_name,
+          png_sizeof(png_ptr->unknown_chunk.name));
       png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
-        = '\0';
+          = '\0';
 
       png_ptr->unknown_chunk.size = (png_size_t)length;
 
@@ -1625,17 +1753,17 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
       else
       {
          png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
-       (png_uint_32)length);
+             (png_size_t)length);
          png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
       }
 
-#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
       if (png_ptr->read_user_chunk_fn != NULL)
       {
          /* Callback to user unknown chunk handler */
          int ret;
          ret = (*(png_ptr->read_user_chunk_fn))
-           (png_ptr, &png_ptr->unknown_chunk);
+             (png_ptr, &png_ptr->unknown_chunk);
 
          if (ret < 0)
             png_chunk_error(png_ptr, "error in user chunk");
@@ -1644,16 +1772,16 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
          {
             if (!(png_ptr->chunk_name[0] & 0x20))
                if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
-                    PNG_HANDLE_CHUNK_ALWAYS)
+                   PNG_HANDLE_CHUNK_ALWAYS)
                   png_chunk_error(png_ptr, "unknown critical chunk");
             png_set_unknown_chunks(png_ptr, info_ptr,
-               &png_ptr->unknown_chunk, 1);
+                &png_ptr->unknown_chunk, 1);
          }
       }
 
       else
 #endif
-        png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+         png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
       png_free(png_ptr, png_ptr->unknown_chunk.data);
       png_ptr->unknown_chunk.data = NULL;
    }
@@ -1687,13 +1815,12 @@ png_push_have_row(png_structp png_ptr, png_bytep row)
 }
 
 void PNGAPI
-png_progressive_combine_row (png_structp png_ptr,
-   png_bytep old_row, png_bytep new_row)
+png_progressive_combine_row (png_structp png_ptr, png_bytep old_row,
+    png_const_bytep new_row)
 {
-#ifdef PNG_USE_LOCAL_ARRAYS
    PNG_CONST int FARDATA png_pass_dsp_mask[7] =
       {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
-#endif
+
    if (png_ptr == NULL)
       return;
 
@@ -1703,8 +1830,8 @@ png_progressive_combine_row (png_structp png_ptr,
 
 void PNGAPI
 png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
-   png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
-   png_progressive_end_ptr end_fn)
+    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+    png_progressive_end_ptr end_fn)
 {
    if (png_ptr == NULL)
       return;
@@ -1717,7 +1844,7 @@ png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
 }
 
 png_voidp PNGAPI
-png_get_progressive_ptr(png_structp png_ptr)
+png_get_progressive_ptr(png_const_structp png_ptr)
 {
    if (png_ptr == NULL)
       return (NULL);