GraphicsMagick crashes in LocaleCompare when working with files which names contains non-English (in my case, Russian) letters. I've firstly noticed it with 1.3.8, but 1.3.10 crashes as well. I've done some investigation and discovered that LocaleCompare() and LocaleNCompare() (and all other functions for processing the character sequences) work with pointers to char, while char type is signed in many platforms by default. Quick and dirty solution is to replace char with unsigned char.
I wonder whether all char sequences processing functions in magick/utility.c should work with unsigned char instead of char.
I use x86_64 platform if it matters. I currently cannot test if it fails on x86.
Steps to repruduce:
1. % gm identify test.png
test.png PNG 320x240+0+0 DirectClass 16-bit 1.3K 0.000u 0:01
2. % gm identify проверка.png
zsh: segmentation fault (core dumped) gm identify проверка.png
Backtrace and test files are to come.