Exit if pngcrush has a bug

tools/resources/optimize-png-files.sh

 #!/bin/bash -i
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # The optimization code is based on pngslim (http://goo.gl/a0XHg)
 # and executes a similar pipleline to optimize the png file size.
 # The steps that require pngoptimizercl/pngrewrite/deflopt are omitted,
 # but this runs all other processes, including:
 # 1) various color-dependent optimizations using optipng.
@@ skipping 363 matching lines @@
 function fail_if_not_installed {
   local program=$1
   local url=$2
   which $program > /dev/null 2>&1
   if [ $? != 0 ]; then
     echo "Couldn't find $program. Please download and install it from $url ."
     exit 1
   fi
 }
 
+# Check pngcrush version and exit if the version is in bad range.
+# See crbug.com/404893.
+function exit_if_bad_pngcrush_version {
+  local version=$(pngcrush -v | awk "/pngcrush 1.7./ {print \$3}")
+  local version_num=$(echo $version | sed "s/\.//g")
+  if [[ (1748 -lt $version_num && $version_num -lt 1773) ]] ; then

[msw, 2014/09/05 19:05:43]

How did you find this range? I'd like to be sure that 1.7.73 and onward does not
have this defect. Will Ubuntu 14.04 LTS users have a clear path to upgrade?
(should we instruct them that they'll need to build source from xyz, since
Ubuntu's package manager only grabs 1.7.65-0.1, and there don't seem to be other
prebuilt Linux binaries?)

+    echo "Your pngcrush ($version) has a bug that exists from " \
+         "1.7.49 to 1.7.72  (see crbug.com/404893 for details)."
+    echo "Please upgrade pngcrush and try again"
+    exit 1;
+  fi
+}
+
 function show_help {
   local program=$(basename $0)
   echo \
 "Usage: $program [options] <dir> ...
 
 $program is a utility to reduce the size of png files by removing
 unnecessary chunks and compressing the image.
 
 Options:
   -o<optimize_level>  Specify optimization level: (default is 1)
@@ skipping 60 matching lines @@
     [h?])
       show_help;;
   esac
 done
 
 # Remove options from argument list.
 shift $(($OPTIND -1))
 
 # Make sure we have all necessary commands installed.
 install_if_not_installed pngcrush pngcrush
+exit_if_bad_pngcrush_version
+
 if [ $OPTIMIZE_LEVEL -ge 1 ]; then
   install_if_not_installed optipng optipng
 
   if $using_cygwin ; then
     fail_if_not_installed advdef "http://advancemame.sourceforge.net/comp-readme.html"
   else
     install_if_not_installed advdef advancecomp
   fi
 
   if $using_cygwin ; then
@@ skipping 50 matching lines @@
 if [ $PROCESSED_FILE != 0 ]; then
   let diff=$TOTAL_OLD_BYTES-$TOTAL_NEW_BYTES
   let percent=$diff*100/$TOTAL_OLD_BYTES
   echo "Result: $TOTAL_OLD_BYTES => $TOTAL_NEW_BYTES bytes" \
        "($diff bytes: $percent%)"
 fi
 if [ $CORRUPTED_FILE != 0 ]; then
   echo "Warning: corrupted files found: $CORRUPTED_FILE"
   echo "Please contact the author of the CL that landed corrupted png files"
 fi