add option to optimize PNG images with optipng

This can decrease package size by optimizing PNG image size. Images are
just stored with better compression and/or filter options. The actual
image content is not altered.

Additionally this can automatically fix broken PNG images which caused
some trouble lately.

Signed-off-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Allan McRae <allan@archlinux.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/doc/makepkg.conf.5.txt b/doc/makepkg.conf.5.txt
index 5e34b916..ac5791fd 100644
--- a/doc/makepkg.conf.5.txt
+++ b/doc/makepkg.conf.5.txt
@@ -140,7 +140,7 @@ Options
 	Specify a key to use for GPG signing instead of the default key in the
 	keyring. Can be overridden with makepkg's '\--key' option.
 
-**OPTIONS=(**strip docs libtool staticlibs emptydirs zipman purge !upx**)**::
+**OPTIONS=(**strip docs libtool staticlibs emptydirs zipman purge !upx !optipng**)**::
 	This array contains options that affect default packaging. They are
 	equivalent to options that can be placed in the PKGBUILD; the defaults are
 	shown here. All options should always be left in the array; to enable or
@@ -181,6 +181,10 @@ Options
 		Compress binary executable files using UPX. Additional options
 		can be passed to UPX by specifying the `UPXFLAGS` array variable.
 
+	*optipng*;;
+		Optimize PNG images with optipng. Additional options can be passed
+		to optipng by specifying the `OPTIPNGFLAGS` array variable.
+
 	*debug*;;
 		Add the user-specified debug flags as specified in DEBUG_CFLAGS and
 		DEBUG_CXXFLAGS to their counterpart buildflags. Creates a separate