Santiago Vila wrote:
Exit status is 0 if inputs are the same, 1 if different, 2 if trouble.
For Diffutils "trouble" means "the output doesn't correctly represent the difference between the two input files". Perhaps that's not what is wanted in this situation with a diff wrapper that supports some binary files but not others, but I expect that there are other uses where the current behavior is wanted. The users in question could change their wrapper to use "diff -a", or to look for the message they don't think is trouble and to ignore exit status 2 in that case.
In theory we could have different exit statuses for Diffutils, one for each sort of trouble, but I'm not sure that's a road we want to head down.
