[libpng15] Suppress clang warnings about implicit sign changes in png.c

3 files changed, 10 insertions, 8 deletions

diff --git a/ANNOUNCE b/ANNOUNCE
index e8590db73..eee9ad91d 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.5.29beta01 - December 30, 2016
+Libpng 1.5.29beta01 - March 1, 2017
 
 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.
@@ -26,7 +26,8 @@ Other information:
 
 Changes since the last public release (1.5.28):
 
-version 1.5.29beta01 [December 30, 2016]
+version 1.5.29beta01 [March 1, 2017]
+  Suppress clang warnings about implicit sign changes in png.c
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 59ace62b4..ca78c608a 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4531,7 +4531,8 @@ version 1.5.28 [December 29, 2016]
   Fixed a potential null pointer dereference in png_set_text_2() (bug report
     and patch by Patrick Keshishian, CVE-2016-10087).
 
-version 1.5.29beta01 [December 30, 2016]
+version 1.5.29beta01 [March 1, 2017]
+  Suppress clang warnings about implicit sign changes in png.c
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/png.c b/png.c
index 460bfe9e5..a9e75cca9 100644
--- a/png.c
+++ b/png.c
@@ -656,14 +656,14 @@ png_get_copyright(png_const_structp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.5.29beta01 - December 30, 2016" PNG_STRING_NEWLINE \
+     "libpng version 1.5.29beta01 - March 1, 2017" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2002,2004,2006-2017 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 1.5.29beta01 - December 30, 2016\
+      return "libpng version 1.5.29beta01 - March 1, 2017\
       Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -2926,13 +2926,13 @@ png_set_option(png_structp png_ptr, int option, int onoff)
    if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT &&
       (option & 1) == 0)
    {
-      int mask = 3 << option;
-      int setting = (2 + (onoff != 0)) << option;
+      int mask = 3U << option;
+      int setting = (2U + (onoff != 0)) << option;
       int current = png_ptr->options;
 
       png_ptr->options = (png_byte)((current & ~mask) | setting);
 
-      return (current & mask) >> option;
+      return (int)(current & mask) >> option;
    }
 
    return PNG_OPTION_INVALID;