ROM name with some strange characters (percent %) doesn't work

[meleu]

[From the RetroPie thread: https://retropie.org.uk/forum/topic/3147/retropie-namingconvention-question]

Based on RetroArch user requests (this forum, libretro forum) and on a personal taste, I did some changes in the RetroArch code for a screenshot naming feature (my Pull Request at RetroArch github)

To make my tests I named a ROM with this filename really 'weird' %%ROM%% name%s%y%m.nes.

When I try to launch this ROM in emulationstation it "freezes", I'm (almost) pretty sure that it is an emulationstation limitation. How can I know it?

1. the runcommand dialog isn't shown;
2. the htop command shows only some emulationstation processes for the user pi;
3. if I hit ctrl+c it kills emulationstation and goes to the bash prompt;
4. if I execute the runcommand from the prompt to load this ROM, RetroArch starts correctly.

Command used to start from the prompt:

/opt/retropie/supplementary/runcommand/runcommand.sh 0 _SYS_ nes ~/RetroPie/roms/nes/really\ \'weird\'\ %%ROM%%\ name%s%y%m.nes 

[c0d3h4x0r]

I've seen similar problems with game names that contain an ampersand (&). I had to rename them to use the word "and" instead.