[libpng17] Port recent /*SAFE*/ comments and manual changes from libpng16

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.7.0beta17 - July 5, 2013
+Libpng 1.7.0beta17 - July 15, 2013
 
 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.
@@ -343,7 +343,10 @@ Version 1.7.0beta16 [July 5, 2013]
   Ported ARM no-read patch from libpng16.
   Ported pngfix.c patches from libpng16.
 
-Version 1.7.0beta17 [July 5, 2013]
+Version 1.7.0beta17 [July 15, 2013]
+  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+    may be erroneously issued by code-checking applications.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4046,7 +4046,9 @@ Version 1.6.0beta17 [March 10, 2012]
   Deflate/inflate was reworked to move common zlib calls into single
     functions [rw]util.c.  A new shared keyword check routine was also added
     and the 'zbuf' is no longer allocated on progressive read.  It is now
-    possible to call png_inflate() incrementally.
+    possible to call png_inflate() incrementally.  A warning is no longer
+    issued if the language tag or translated keyword in the iTXt chunk
+    has zero length.
   If benign errors are disabled use maximum window on ancilliary inflate.
     This works round a bug introduced in 1.5.4 where compressed ancillary
     chunks could end up with a too-small windowBits value in the deflate
@@ -4631,7 +4633,10 @@ Version 1.7.0beta16 [July 5, 2013]
   Ported ARM no-read patch from libpng16.
   Ported pngfix.c patches from libpng16.
 
-Version 1.7.0beta17 [July 5, 2013]
+Version 1.7.0beta17 [July 15, 2013]
+  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+    may be erroneously issued by code-checking applications.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

libpng-manual.txt

@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.7.0beta17 - July 5, 2013
+ libpng version 1.7.0beta17 - July 15, 2013
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta17 - July 5, 2013
+ libpng versions 0.97, January 1998, through 1.7.0beta17 - July 15, 2013
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
@@ -2288,7 +2288,7 @@ For a more compact example of reading a PNG image, see the file example.c.
 
 Reading PNG files progressively
 
-The progressive reader is slightly different then the non-progressive
+The progressive reader is slightly different from the non-progressive
 reader.  Instead of calling png_read_info(), png_read_rows(), and
 png_read_end(), you make one call to png_process_data(), which calls
 callbacks when it has the info, a row, or the end of the image.  You
@@ -5005,6 +5005,10 @@ even if the image only contains gray pixels, only RGB profiles may appear
 in images with color type 2, 3, or 6, is now enforced.  The sRGB chunk
 is allowed to appear in images with any color type.
 
+Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
+an empty language field or an empty translated keyword.  Both of these
+are allowed by the PNG specification, so these warnings are no longer issued.
+
 The library now issues an error if the application attempts to set a
 transform after it calls png_read_update_info().
 
@@ -5236,7 +5240,7 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVII. Y2K Compliance in libpng
 
-July 5, 2013
+July 15, 2013
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.

libpng.3

@@ -1,4 +1,4 @@
-.TH LIBPNG 3 "July 5, 2013"
+.TH LIBPNG 3 "July 15, 2013"
 .SH NAME
 libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta17
 .SH SYNOPSIS
@@ -494,7 +494,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.7.0beta17 - July 5, 2013
+ libpng version 1.7.0beta17 - July 15, 2013
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -505,7 +505,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta17 - July 5, 2013
+ libpng versions 0.97, January 1998, through 1.7.0beta17 - July 15, 2013
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
@@ -2782,7 +2782,7 @@ For a more compact example of reading a PNG image, see the file example.c.
 
 .SS Reading PNG files progressively
 
-The progressive reader is slightly different then the non-progressive
+The progressive reader is slightly different from the non-progressive
 reader.  Instead of calling png_read_info(), png_read_rows(), and
 png_read_end(), you make one call to png_process_data(), which calls
 callbacks when it has the info, a row, or the end of the image.  You
@@ -5500,6 +5500,10 @@ even if the image only contains gray pixels, only RGB profiles may appear
 in images with color type 2, 3, or 6, is now enforced.  The sRGB chunk
 is allowed to appear in images with any color type.
 
+Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
+an empty language field or an empty translated keyword.  Both of these
+are allowed by the PNG specification, so these warnings are no longer issued.
+
 The library now issues an error if the application attempts to set a
 transform after it calls png_read_update_info().
 
@@ -5731,7 +5735,7 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XVII. Y2K Compliance in libpng
 
-July 5, 2013
+July 15, 2013
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
@@ -6001,7 +6005,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.7.0beta17 - July 5, 2013:
+Libpng version 1.7.0beta17 - July 15, 2013:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6024,7 +6028,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.7.0beta17, July 5, 2013, are
+libpng versions 1.2.6, August 15, 2004, through 1.7.0beta17, July 15, 2013, are
 Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
@@ -6123,7 +6127,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-July 5, 2013
+July 15, 2013
 
 .\" end of man page
 

pngpread.c

@@ -151,7 +151,7 @@ png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
 void /* PRIVATE */
 png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
 {
-   png_size_t num_checked = png_ptr->sig_bytes,
+   png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ 
              num_to_check = 8 - num_checked;
 
    if (png_ptr->buffer_size < num_to_check)

pngrutil.c

@@ -3654,7 +3654,7 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
 
             for (i = 0; i < row_info->width; i++)
             {
-               png_byte v[8];
+               png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
                int j;
 
                memcpy(v, sp, pixel_bytes);