[libpng17] Merge recent changes from libpng-1.6.14beta06:

Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
Removed unused "text_len" parameter from private function png_write_zTXt().
Conditionally compile some code in png_deflate_claim(), when
  PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
  to pnglibconf.dfa.
Edit and fix typos in comments.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.7.0beta38 - September 28, 2014
+Libpng 1.7.0beta38 - October 4, 2014
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -602,7 +602,14 @@ Version 1.7.0beta36 [September 27, 2014]
 Version 1.7.0beta37 [September 28, 2014]
   Merged scripts/*, pngvalid.c and pngfix.c with libpng-1.6.14beta04.
 
-Version 1.7.0beta38 [September 28, 2014]
+Version 1.7.0beta38 [October 4, 2014]
+  Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
+  Removed unused "text_len" parameter from private function png_write_zTXt().
+  Conditionally compile some code in png_deflate_claim(), when
+    PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
+  Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
+  Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
+    to pnglibconf.dfa.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4891,7 +4891,14 @@ Version 1.7.0beta36 [September 27, 2014]
 Version 1.7.0beta37 [September 28, 2014]
   Merged scripts/*, pngvalid.c and pngfix.c with libpng-1.6.14beta04.
 
-Version 1.7.0beta38 [September 28, 2014]
+Version 1.7.0beta38 [October 4, 2014]
+  Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
+  Removed unused "text_len" parameter from private function png_write_zTXt().
+  Conditionally compile some code in png_deflate_claim(), when
+    PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
+  Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
+  Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
+    to pnglibconf.dfa.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

png.c

@@ -696,13 +696,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.7.0beta38 - September 28, 2014" PNG_STRING_NEWLINE \
+     "libpng version 1.7.0beta38 - October 4, 2014" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2014 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-      return "libpng version 1.7.0beta38 - September 28, 2014\
+      return "libpng version 1.7.0beta38 - October 4, 2014\
       Copyright (c) 1998-2014 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -3474,8 +3474,8 @@ png_log16bit(png_uint_32 x)
  * each case only the low 16 bits are relevant - the fraction - since the
  * integer bits (the top 4) simply determine a shift.
  *
- * The worst case is the 16-bit distinction between 65535 and 65534, this
+ * The worst case is the 16-bit distinction between 65535 and 65534. This
- * requires perhaps spurious accuracty in the decoding of the logarithm to
+ * requires perhaps spurious accuracy in the decoding of the logarithm to
  * distinguish log2(65535/65534.5) - 10^-5 or 17 bits.  There is little chance
  * of getting this accuracy in practice.
  *
@@ -3563,7 +3563,7 @@ png_exp8bit(png_fixed_point lg2)
    /* Get a 32-bit value: */
    png_uint_32 x = png_exp(lg2);
 
-   /* Convert the 32-bit value to 0..255 by multiplying by 256-1, note that the
+   /* Convert the 32-bit value to 0..255 by multiplying by 256-1. Note that the
     * second, rounding, step can't overflow because of the first, subtraction,
     * step.
     */
@@ -4165,7 +4165,7 @@ png_set_option(png_structrp png_ptr, int option, int onoff)
  *
  *    error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact
  *
- * In all cases the inexact readings are off by one.
+ * In all cases the inexact readings are only off by one.
  */
 
 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED

pngpread.c

@@ -26,6 +26,13 @@
 #define PNG_READ_iTXt_MODE  7
 #define PNG_ERROR_MODE      8
 
+#define PNG_PUSH_SAVE_BUFFER_IF_FULL \
+if (png_ptr->push_length + 4 > png_ptr->buffer_size) \
+   { png_push_save_buffer(png_ptr); return; }
+#define PNG_PUSH_SAVE_BUFFER_IF_LT_N(N) \
+if (png_ptr->buffer_size < N) \
+   { png_push_save_buffer(png_ptr); return; }
+
 void PNGAPI
 png_process_data(png_structrp png_ptr, png_inforp info_ptr,
     png_bytep buffer, png_size_t buffer_size)
@@ -46,7 +53,7 @@ png_process_data_pause(png_structrp png_ptr, int save)
 {
    if (png_ptr != NULL)
    {
-      /* It's easiest for the caller if we do the save, then the caller doesn't
+      /* 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 != 0)
@@ -189,10 +196,10 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
    int keep; /* unknown handling method */
 #endif
 
-   /* First we make sure we have enough data for the 4 byte chunk name
+   /* 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
+    * and the 4-byte chunk length before proceeding with decoding the
     * chunk data.  To fully decode each of these chunks, we also make
-    * sure we have enough data in the buffer for the 4 byte CRC at the
+    * sure we have enough data in the buffer for the 4-byte CRC at the
     * end of every chunk (except IDAT, which is handled separately).
     */
    if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
@@ -200,12 +207,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
       png_byte chunk_length[4];
       png_byte chunk_tag[4];
 
-      if (png_ptr->buffer_size < 8)
+      PNG_PUSH_SAVE_BUFFER_IF_LT_N(8)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_push_fill_buffer(png_ptr, chunk_length, 4);
       png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
@@ -249,23 +251,13 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
       if (png_ptr->push_length != 13)
          png_error(png_ptr, "Invalid IHDR length");
 
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
    }
 
    else if (chunk_name == png_IEND)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
 
       png_ptr->process_mode = PNG_READ_DONE_MODE;
@@ -275,12 +267,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
    else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
 
       if (chunk_name == png_PLTE)
@@ -290,11 +277,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
    else if (chunk_name == png_PLTE)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
       png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -313,12 +296,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_gAMA_SUPPORTED
    else if (png_ptr->chunk_name == png_gAMA)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -326,12 +304,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sBIT_SUPPORTED
    else if (png_ptr->chunk_name == png_sBIT)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -339,12 +312,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_cHRM_SUPPORTED
    else if (png_ptr->chunk_name == png_cHRM)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -352,12 +320,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sRGB_SUPPORTED
    else if (chunk_name == png_sRGB)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -365,12 +328,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_iCCP_SUPPORTED
    else if (png_ptr->chunk_name == png_iCCP)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -378,12 +336,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sPLT_SUPPORTED
    else if (chunk_name == png_sPLT)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -391,12 +344,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_tRNS_SUPPORTED
    else if (chunk_name == png_tRNS)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -404,12 +352,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_bKGD_SUPPORTED
    else if (chunk_name == png_bKGD)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -417,12 +360,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_hIST_SUPPORTED
    else if (chunk_name == png_hIST)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -430,12 +368,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_pHYs_SUPPORTED
    else if (chunk_name == png_pHYs)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -443,12 +376,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_oFFs_SUPPORTED
    else if (chunk_name == png_oFFs)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
    }
 #endif
@@ -456,12 +384,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_pCAL_SUPPORTED
    else if (chunk_name == png_pCAL)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -469,12 +392,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sCAL_SUPPORTED
    else if (chunk_name == png_sCAL)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -482,12 +400,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_tIME_SUPPORTED
    else if (chunk_name == png_tIME)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -495,12 +408,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_tEXt_SUPPORTED
    else if (chunk_name == png_tEXt)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -508,12 +416,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_zTXt_SUPPORTED
    else if (chunk_name == png_zTXt)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -521,23 +424,14 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_iTXt_SUPPORTED
    else if (chunk_name == png_iTXt)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 #endif
 
    else
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
       png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
          PNG_HANDLE_CHUNK_AS_DEFAULT);
    }
@@ -602,12 +496,7 @@ png_push_crc_finish(png_structrp png_ptr)
    }
    if (!png_ptr->skip_length)
    {
-      if (png_ptr->buffer_size < 4)
+      PNG_PUSH_SAVE_BUFFER_IF_LT_N(4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_crc_finish(png_ptr, 0);
       png_ptr->process_mode = PNG_READ_CHUNK_MODE;
    }
@@ -732,12 +621,7 @@ png_push_read_IDAT(png_structrp png_ptr)
       png_byte chunk_tag[4];
 
       /* TODO: this code can be commoned up with the same code in push_read */
-      if (png_ptr->buffer_size < 8)
+      PNG_PUSH_SAVE_BUFFER_IF_LT_N(8)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_push_fill_buffer(png_ptr, chunk_length, 4);
       png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
@@ -812,12 +696,7 @@ png_push_read_IDAT(png_structrp png_ptr)
    }
    if (!png_ptr->idat_size)
    {
-      if (png_ptr->buffer_size < 4)
+      PNG_PUSH_SAVE_BUFFER_IF_LT_N(4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
       png_crc_finish(png_ptr, 0);
       png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
       png_ptr->mode |= PNG_AFTER_IDAT;

pngpriv.h

@@ -998,7 +998,7 @@ PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
 
 #ifdef PNG_WRITE_zTXt_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
-    key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
+    key, png_const_charp text, int compression),PNG_EMPTY);
 #endif
 
 #ifdef PNG_WRITE_iTXt_SUPPORTED

pngset.c

@@ -727,7 +727,7 @@ png_set_text_2(png_structrp png_ptr, png_inforp info_ptr,
          else
             max_text = INT_MAX;
 
-         /* Now allocate a new array and copy the old members in, this does all
+         /* Now allocate a new array and copy the old members in; this does all
           * the overflow checks.
           */
          new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
@@ -1061,8 +1061,8 @@ png_set_sPLT(png_structrp png_ptr,
 
       np->depth = entries->depth;
 
-      /* In the even of out-of-memory just return - there's no point keeping on
+      /* In the event of out-of-memory just return - there's no point keeping
-       * trying to add sPLT chunks.
+       * on trying to add sPLT chunks.
        */
       length = strlen(entries->name) + 1;
       np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
@@ -1073,8 +1073,8 @@ png_set_sPLT(png_structrp png_ptr,
       memcpy(np->name, entries->name, length);
 
       /* IMPORTANT: we have memory now that won't get freed if something else
-       * goes wrong, this code must free it.  png_malloc_array produces no
+       * goes wrong; this code must free it.  png_malloc_array produces no
-       * warnings, use a png_chunk_report (below) if there is an error.
+       * warnings; use a png_chunk_report (below) if there is an error.
        */
       np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
           entries->nentries, sizeof (png_sPLT_entry)));
@@ -1113,7 +1113,7 @@ check_location(png_const_structrp png_ptr, int location)
    location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
 
    /* New in 1.6.0; copy the location and check it.  This is an API
-    * change, previously the app had to use the
+    * change; previously the app had to use the
     * png_set_unknown_chunk_location API below for each chunk.
     */
    if (location == 0 && !(png_ptr->mode & PNG_IS_READ_STRUCT))

pngtrans.c

@@ -828,7 +828,7 @@ png_get_user_transform_ptr(png_const_structrp png_ptr)
 png_uint_32 PNGAPI
 png_get_current_row_number(png_const_structrp png_ptr)
 {
-   /* See the comments in png.h - this is the sub-image row when reading and
+   /* See the comments in png.h - this is the sub-image row when reading an
     * interlaced image.
     */
    if (png_ptr != NULL)

pngwrite.c

@@ -310,8 +310,7 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
 #ifdef PNG_WRITE_zTXt_SUPPORTED
          /* Write compressed chunk */
          png_write_zTXt(png_ptr, info_ptr->text[i].key,
-             info_ptr->text[i].text, 0,
+             info_ptr->text[i].text, info_ptr->text[i].compression);
-             info_ptr->text[i].compression);
 #else
          png_warning(png_ptr, "Unable to write compressed text");
 #endif
@@ -404,8 +403,7 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_WRITE_zTXt_SUPPORTED
             /* Write compressed chunk */
             png_write_zTXt(png_ptr, info_ptr->text[i].key,
-                info_ptr->text[i].text, 0,
+                info_ptr->text[i].text, info_ptr->text[i].compression);
-                info_ptr->text[i].compression);
 #else
             png_warning(png_ptr, "Unable to write compressed text");
 #endif

pngwutil.c

@@ -136,7 +136,7 @@ png_write_chunk_data(png_structrp png_ptr, png_const_bytep data,
       png_write_data(png_ptr, data, length);
 
       /* Update the CRC after writing the data,
-       * in case that the user I/O routine alters it.
+       * in case the user I/O routine alters it.
        */
       png_calculate_crc(png_ptr, data, length);
    }
@@ -181,7 +181,7 @@ png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
 
    /* On 64 bit architectures 'length' may not fit in a png_uint_32. */
    if (length > PNG_UINT_31_MAX)
-      png_error(png_ptr, "length exceeds PNG maxima");
+      png_error(png_ptr, "length exceeds PNG maximum");
 
    png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
    png_write_chunk_data(png_ptr, data, length);
@@ -204,7 +204,7 @@ png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
 static png_alloc_size_t
 png_image_size(png_structrp png_ptr)
 {
-   /* Only return sizes up to the maximum of a png_uint_32, do this by limiting
+   /* Only return sizes up to the maximum of a png_uint_32; do this by limiting
     * the width and height used to 15 bits.
     */
    png_uint_32 h = png_ptr->height;
@@ -297,6 +297,7 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
 {
    if (png_ptr->zowner != 0)
    {
+#     if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
       char msg[64];
 
       PNG_STRING_FROM_CHUNK(msg, owner);
@@ -308,6 +309,7 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
        * are minimal.
        */
       (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
+#     endif
 #     if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
          png_warning(png_ptr, msg);
 
@@ -492,7 +494,7 @@ png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
    int ret;
 
    /* To find the length of the output it is necessary to first compress the
-    * input, the result is buffered rather than using the two-pass algorithm
+    * input. The result is buffered rather than using the two-pass algorithm
     * that is used on the inflate side; deflate is assumed to be slower and a
     * PNG writer is assumed to have more memory available than a PNG reader.
     *
@@ -589,7 +591,7 @@ png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
       }
       while (ret == Z_OK);
 
-      /* There may be some space left in the last output buffer, this needs to
+      /* There may be some space left in the last output buffer. This needs to
        * be subtracted from output_len.
        */
       output_len -= png_ptr->zstream.avail_out;
@@ -612,7 +614,7 @@ png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
       /* Reset zlib for another zTXt/iTXt or image data */
       png_ptr->zowner = 0;
 
-      /* The only success case is Z_STREAM_END, input_len must be 0, if not this
+      /* The only success case is Z_STREAM_END, input_len must be 0; if not this
        * is an internal error.
        */
       if (ret == Z_STREAM_END && input_len == 0)
@@ -728,6 +730,7 @@ png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
    if (key_len == 0)
       return 0;
 
+#ifdef PNG_WARNINGS_SUPPORTED
    /* Try to only output one warning per keyword: */
    if (*key) /* keyword too long */
       png_warning(png_ptr, "keyword truncated");
@@ -741,6 +744,7 @@ png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
 
       png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
    }
+#endif /* PNG_WARNINGS_SUPPORTED */
 
    return key_len;
 }
@@ -998,7 +1002,7 @@ png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
  * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
  *
  * The routine manages the acquire and release of the png_ptr->zstream by
- * checking and (at the end) clearing png_ptr->zowner, it does some sanity
+ * checking and (at the end) clearing png_ptr->zowner; it does some sanity
  * checks on the 'mode' flags while doing this.
  */
 void /* PRIVATE */
@@ -1058,7 +1062,7 @@ png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
       input_len += png_ptr->zstream.avail_in;
       png_ptr->zstream.avail_in = 0;
 
-      /* OUTPUT: write complete IDAT chunks when avail_out drops to zero, note
+      /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note
        * that these two zstream fields are preserved across the calls, therefore
        * there is no need to set these up on entry to the loop.
        */
@@ -1090,7 +1094,7 @@ png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
             continue;
       }
 
-      /* The order of these checks doesn't matter much; it just effect which
+      /* The order of these checks doesn't matter much; it just affects which
        * possible error might be detected if multiple things go wrong at once.
        */
       if (ret == Z_OK) /* most likely return code! */
@@ -1623,14 +1627,13 @@ png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
 /* Write a compressed text chunk */
 void /* PRIVATE */
 png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
-    png_size_t text_len, int compression)
+    int compression)
 {
    png_uint_32 key_len;
    png_byte new_key[81];
    compression_state comp;
 
    png_debug(1, "in png_write_zTXt");
-   PNG_UNUSED(text_len) /* Always use strlen */
 
    if (compression == PNG_TEXT_COMPRESSION_NONE)
    {

scripts/pnglibconf.dfa

@@ -740,7 +740,7 @@ chunk cHRM enables COLORSPACE
 chunk gAMA enables GAMMA
 chunk hIST
 chunk iCCP enables COLORSPACE, GAMMA
-chunk iTXt
+chunk iTXt enables TEXT
 chunk oFFs
 chunk pCAL
 chunk pHYs
@@ -751,7 +751,7 @@ chunk sRGB enables COLORSPACE, GAMMA, SET_OPTION
 chunk tEXt requires TEXT
 chunk tIME
 chunk tRNS
-chunk zTXt
+chunk zTXt enables TEXT
 
 # This only affects support of the optional PLTE chunk in RGB and RGBA
 # images.  Notice that READ_ANCILLARY_CHUNKS therefore disables part
@@ -835,9 +835,9 @@ option SAVE_INT_32 disabled
 option WRITE_OPTIMIZE_CMF requires WRITE
 
 option READ_COMPRESSED_TEXT disabled
+option READ_iCCP enables READ_COMPRESSED_TEXT
 option READ_iTXt enables READ_COMPRESSED_TEXT
 option READ_zTXt enables READ_COMPRESSED_TEXT
-option READ_COMPRESSED_TEXT enables READ_TEXT
 
 option WRITE_oFFs enables SAVE_INT_32
 option WRITE_pCAL enables SAVE_INT_32