On 2020-08-13 17:50:31-0700, Junio C Hamano <gitster@xxxxxxxxx> wrote: > Đoàn Trần Công Danh <congdanhqx@xxxxxxxxx> writes: > > > When we see --no-abbrev in command's arguments, we reset the 'abbrev' > > field in diff-options to 0 and this value will be looked at > > diff_abbrev_oid() to decide not to truncate the object name. > > > > In a later change, we want to extend --abbrev support to diff-patch > > format. When --abbrev supporting diff-patch, we need to differentiate > > those below scenarios: > > > > * None of those options --abbrev, --no-abbrev, and --full-index are > > asked. diff-patch should keep old behavior of using DEFAULT_ABBREV > > for the index length. > > * --no-abbrev is asked, diff-patch should treat this option as same as > > --full-index and show full object name in index line. > > Sorry, but are you saying that the above two cases cannot be > differentiated in the current code? > > * If none of --abbrev, --no-abbrev, --full-index are given, then > diff.c::prep_parse_options() will leave options->flags.full_index > and options->abbrev untouched. They are initialized to false and > DEFAULT_ABBREV (typically -1 when unconfigured). > > * If --no-abbrev is given, options->abbrev is set to 0. > options->flags.full_index is not touched. > > So you should be able to tell these two apart by only looking at > options->flags.full_index bit. Perhaps, even though you said "we > need to differentiate", you meant something else? Oops, I shouldn't say anything about --full-index in the second point to reduce confusion. Let me list some combination here: * none of --abbrev --no-abbrev --full-index -> default short index * --abbrev --full-index -> full-index * --full-index --abbrev -> full-index * --abbrev --no-abbrev -> full-index * --no-abbrev --abbrev=[n] -> shortened index to n char So, we can't use full_index bit, because --no-abbrev can be defeated by --abbrev, but --full-index will always win --abbrev. > > > While not doing anything is very effective way to show full object id, > > we couldn't differentiate if --no-abbrev or not. > > Hmph. --no-abbrev without --full-index would not set > flags.full_index bit; using --full-index would set the bit. Are you > planning to do something special when BOTH --no-abbrev and --full-index > is given? I am confused X-<. I'm not planning for anything special when both --no-abbrev and --full-index is given. I'm planning for: * BOTH --abbrev and --no-abbrev but NOT --full-index; * BOTH --abbrev AND --full-index Sorry for the confusion, I hope it's clear now, and you could help me rephase a bit to reduce confusion. -- Danh
