Arch Linux

Thanks for reporting, I will fix this.

Thanks for looking into these issues. I spotted a few other things as well, so I thought I would mention them just in case it is helpful in some way.

I noticed that you are patching the original source code with this line:
sed -i 's:openjpeg.h:openjpeg-1.5/openjpeg.h:' src/png.c

You can achieve the same thing by using this in the CFLAGS environment variable:
pkg-config libopenjpeg --cflags

Using sed to patch source code achieves the same thing, but sed is a blunt instrument and could cause unintended problems that pkg-config is designed to avoid.

On the subject of CFLAGS, I noticed this line in PKGBUILD:

export CFLAGS="`pkg-config gtk+-2.0 --cflags` $CFLAGS"

I think this could this be changed to this:

export CFLAGS="`pkg-config libopenjpeg --cflags` $CFLAGS"

The configure line could then be:

./configure --prefix=/usr --mandir=/usr/share/man man intl GIF jpeg tiff cflags

The cflags argument at the end is needed to force the configure script to use the CFLAGS environment variable.

Lastly, just out of curiosity, why did you decide to suppress compiler warnings with "gcc -w"?

Thanks for the advice! I agree that sed is a blunt tool that often is best to be avoided.

mtpaint was a package I adopted from someone else, so many of the choices that have been made in the PKGBUILD have not originally been mine.

"gcc -w" was just to make the build process less noisy when building the package. Most users will install the pre-compiled mtpaint package, so this is mostly for package maintainers (or people building mtpaint themselves, in which case they may have several things they wish to change. They can change the configure and compilation flags as they desire.)

Updated mtpaint. Please reopen this issue, file a new issue or even contact me directly if there should be further issues or room for improvement with the package.

Thanks for creating mtpaint in the first place as well. :)