Sergey Organov <sorganov@xxxxxxxxx> writes:
> Move specific handling of "-m" for diff-index to diff-index.c, so
> diff-merges is left to handle only diff for merges options.
>
> Being a better design by itself, this is especially essential in
> preparation for letting -m imply -p, as "diff-index -m" obviously
> should not imply -p, as it's entirely unrelated.
>
> To handle this, in addition to moving specific diff-index "-m" code
> out of diff-merges, we introduce new
>
> diff_merges_suppress_options_parsing()
>
> and call it before generic options processing in cmd_diff_index().
This change has a small but obvious fallout.
$ git diff-index -c --cached HEAD^
now starts failing loudly. Earlier, it silently fell back to
"combined" diff of one parent, which is "-p".
I think the end result is good (and luckily, "DIFF FORMAT FOR
MERGES" section explicitly limits "-c" and "--cc" to diff-tree,
diff-files and diff (and by implication excludes diff-index) so I am
sure there are small but non-zero number of people somewhere in the
world who has "diff-index -c" in their scripts that suddenly starts
failing with the version of Git with this change, but we can just
say their use was broken ;-)
