git/diff-merges.c, branch v2.31.2

diff-merges: add '--diff-merges=1' as synonym for 'first-parent'

2020-12-21T21:47:32Z

As we now have --diff-merges={m|c|cc}, add --diff-merges=1 as synonym for --diff-merges=first-parent, to have shorter mnemonics for it as well. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: add old mnemonic counterparts to --diff-merges

2020-12-21T21:47:32Z

This adds --diff-merges={m|c|cc} values that match mnemonics of old options, for those who are used to them. Note that, say, --diff-meres=cc behaves differently than --cc, as the latter implies -p and therefore enables diffs for all the commits, while the former enables output of diffs for merge commits only. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: let new options enable diff without -p

2020-12-21T21:47:32Z

New options don't have any visible effect unless -p is either given or implied, as unlike -c/-cc we don't imply -p with --diff-merges. To fix this, this patch adds new functionality by letting new options enable output of diffs for merge commits only. Add 'merges_need_diff' field and set it whenever diff output for merges is enabled by any of the new options. Extend diff output logic accordingly, to output diffs for merges when 'merges_need_diff' is set even when no -p has been provided. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: do not imply -p for new options

2020-12-21T21:47:32Z

Add 'combined_imply_patch' field and set it only for old --cc/-c options, then imply -p if this flag is set instead of implying -p whenever 'combined_merge' flag is set. We don't want new --diff-merge options to imply -p, to make it possible to enable output of diffs for merges independently from non-merge commits. At the same time we want to preserve behavior of old --c/-c/-m options and their interactions with --first-parent, to stay backward-compatible. This patch is first step in this direction: it separates old "--cc/-c imply -p" logic from the rest of the options. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: implement new values for --diff-merges

2020-12-21T21:47:32Z

We first implement new options as exact synonyms for their original counterparts, to get all the infrastructure right, and keep functional improvements for later commits. The following values are implemented: --diff-merges= old equivalent first|first-parent = --first-parent (only format implications) sep|separate = -m comb|combined = -c dense| dense-combined = --cc Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: make -m/-c/--cc explicitly mutually exclusive

2020-12-21T21:47:31Z

-c/--cc got precedence over -m only because of external logic where corresponding flags are checked before that for -m. This is too error-prone, so add code that explicitly makes these 3 options mutually exclusive, so that the last option specified on the command-line gets precedence. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: refactor opt settings into separate functions

2020-12-21T21:47:31Z

To prepare introduction of new options some of which will be synonyms to existing options, let every option handling code just call corresponding function. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: get rid of now empty diff_merges_init_revs()

2020-12-21T21:47:31Z

After getting rid of 'ignore_merges' field, the diff_merges_init_revs() function became empty. Get rid of it. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: split 'ignore_merges' field

2020-12-21T21:47:31Z

'ignore_merges' was 3-way field that served two distinct purposes that we now assign to 2 new independent flags: 'separate_merges', and 'explicit_diff_merges'. 'separate_merges' tells that we need to output diff format containing separate diff for every parent (as opposed to 'combine_merges'). 'explicit_diff_merges' tells that at least one of diff-merges options has been explicitly specified on the command line, so no defaults should apply. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff-merges: fix -m to properly override -c/--cc

2020-12-21T21:47:31Z

Logically, -m, -c, --cc specify 3 different formats for representing merge commits, yet -m doesn't in fact override -c or --cc, that makes no sense. Fix -m to properly override -c/--cc, and change the tests accordingly. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano