Re: [PATCH 00/26] git-log: implement new --diff-merge options

Elijah Newren [off-list ref] writes:

....  I know what
diff --exit-code does, but I'm really not sure what git-log's
--exit-code does (random guess: sets the exit code to an OR of what
git diff would have shown for any one of the commits shown?).

The end of cmd_log_walk() does try to return diff_result_code(), but
diff_flush() can reset .has_changes to 0 or set it to 1 each
iteration, so I do not think it is "set .has_changes to 0, and never
reset to 0, but flip it to 1 if any change is found", which would
have had some chance of giving us "OR'ed together" semantics.