On Mon, Dec 05, 2016 at 01:01:16AM -0500, Jeff King wrote: > Note that setting abbrev to "0" outside of a repository was broken > recently by 4f03666ac (diff: handle sha1 abbreviations outside of > repository, 2016-10-20). It adds a special out-of-repo code path for > handling abbreviations which behaves differently than find_unique_abbrev() > by truly giving a zero-length sha1, rather than taking "0" to mean "do > not abbreviate". > > That bug was not triggerable until now, because there was no way to > set the value to zero (using --abbrev=0 silently bumps it to the > MINIMUM_ABBREV). Actually, I take this last paragraph back. You _can_ trigger the bug with just: echo one >foo echo two >bar git diff --no-index --raw foo bar which prints only "..." for each entry. I didn't notice it before because without "--raw", we show the patch format. That uses the --full-index option, and does not respect --abbrev at all (which seems kind of bizarre, but has been that way forever). So I think there _is_ a regression in v2.11, and the second half of your change fixes it. -Peff