[bug-diffutils] bug#16608: bug#16608: Bug#737180: diffutils: diff exit status is 2 instead of 1 on binary files that differ (fwd)

[Paul Eggert]

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.