[PATCH v2] log: add option to search for header or body

From: =?UTF-8?q?Max=20=F0=9F=91=A8=F0=9F=8F=BD=E2=80=8D=F0=9F=92=BB=20Copl?=
 =?UTF-8?q?an?= <mchcopl@gmail.com>

Summary: This change adds a new option to `git log` that allows users to search for commits that match either the author or the commit message. This is useful for finding commits that were either authored or co-authored by a specific person.

Currently, the best way to find a commit either authored or co-authored by a specific person is to use

```sh
$ echo \
    $(git log --author=Torvalds --pretty="%cd,%H\n" --date=iso-strict) \
    $(git log --grep="Co-authored-by: .*Torvalds" --pretty="%cd,%H\n" --date=iso-strict) \
| sort -n --reverse \
| awk -F, '{print $2}' \
| tr '\n' '\t' \
| xargs git show --stat --stdin
```

This is a bit of a pain, so this change adds a new option to `git log`. Now finding either authors or co-authors is as simple as

```sh $ git log --author=Torvalds --grep=Torvalds --match-header-or-grep ```

Test plan:
1. create commit authored by A and co-authored-by B
2. create commit authored by B
3. run
```sh
$ git log --author=B --grep="Co-authored-by: B" --match-header-or-grep
```
4. expect to see both commits

Signed-off-by: Max 👨🏽‍💻 Coplan <mchcopl@gmail.com>
---
    log: add option to search for header or body

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1710%2Fvegerot%2Fheader-or-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1710/vegerot/header-or-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1710

Range-diff vs v1:

 1:  dc6b5664159 ! 1:  c7f14e59b4f feat(log): add option to search for header or body to `git log`
     @@ Metadata
      Author: Max 👨🏽‍💻 Coplan <mchcopl@gmail.com>
      
       ## Commit message ##
     -    feat(log): add option to search for header or body to `git log`
     -
     -    Note to reviewer: I hate the name `--header-or`!  Please help me come up
     -    with a better name.
     +    log: add option to search for header or body
      
          Summary:
          This change adds a new option to `git log` that allows users to search
     @@ Commit message
          by a specific person is to use
      
          ```sh
     -    echo \
     +    $ echo \
              $(git log --author=Torvalds --pretty="%cd,%H\n" --date=iso-strict) \
              $(git log --grep="Co-authored-by: .*Torvalds" --pretty="%cd,%H\n" --date=iso-strict) \
          | sort -n --reverse \
     @@ Commit message
          Now finding either authors or co-authors is as simple as
      
          ```sh
     -    git log --author=Torvalds --grep=Torvalds --header-or
     +    $ git log --author=Torvalds --grep=Torvalds --match-header-or-grep
          ```
      
          Test plan:
          1. create commit authored by A and co-authored-by B
          2. create commit authored by B
     -    3. run `git log --author=B --grep="Co-authored-by: B" --header-or`
     +    3. run
     +    ```sh
     +    $ git log --author=B --grep="Co-authored-by: B" --match-header-or-grep
     +    ```
          4. expect to see both commits
      
          Signed-off-by: Max 👨🏽‍💻 Coplan <mchcopl@gmail.com>
      
     + ## Documentation/rev-list-options.txt ##
     +@@ Documentation/rev-list-options.txt: endif::git-rev-list[]
     + 	Limit the commits output to ones that match all given `--grep`,
     + 	instead of ones that match at least one.
     + 
     ++--match-header-or-grep::
     ++	Limit the commits output to ones that match either header patterns
     ++	(`--author`, `--committer`, or `--grep-reflog`) or `--grep`, instead
     ++	of ones that match both the header and grep patterns
     +++
     ++For example, `--author=me --grep=Co-authored-by: me` limits to commits either
     ++authored or co-authored by me.
     ++
     + --invert-grep::
     + 	Limit the commits output to ones with a log message that do not
     + 	match the pattern specified with `--grep=<pattern>`.
     +
     + ## contrib/completion/git-completion.bash ##
     +@@ contrib/completion/git-completion.bash: __git_log_gitk_options="
     + # Options that go well for log and shortlog (not gitk)
     + __git_log_shortlog_options="
     + 	--author= --committer= --grep=
     +-	--all-match --invert-grep
     ++	--all-match --invert-grep --match-header-or-grep
     + "
     + # Options accepted by log and show
     + __git_log_show_options="
     +
       ## grep.c ##
      @@ grep.c: void compile_grep_patterns(struct grep_opt *opt)
     - 	if (opt->no_body_match && opt->pattern_expression)
     - 		opt->pattern_expression = grep_not_expr(opt->pattern_expression);
     - 
     --	if (!header_expr)
     -+	if (!header_expr || opt->header_or)
     - 		return;
       
       	if (!opt->pattern_expression)
     + 		opt->pattern_expression = header_expr;
     +-	else if (opt->all_match)
     ++	else if (opt->all_match || opt->match_header_or_grep)
     + 		opt->pattern_expression = grep_splice_or(header_expr,
     + 							 opt->pattern_expression);
     + 	else
     +@@ grep.c: int grep_source(struct grep_opt *opt, struct grep_source *gs)
     + 	opt->body_hit = 0;
     + 	grep_source_1(opt, gs, 1);
     + 
     +-	if (opt->all_match && !chk_hit_marker(opt->pattern_expression))
     ++	if (!opt->match_header_or_grep && opt->all_match && !chk_hit_marker(opt->pattern_expression))
     + 		return 0;
     + 	if (opt->no_body_match && opt->body_hit)
     + 		return 0;
      
       ## grep.h ##
      @@ grep.h: struct grep_opt {
       	int count;
       	int word_regexp;
       	int all_match;
     -+	int header_or;
     ++	int match_header_or_grep;
       	int no_body_match;
       	int body_hit;
       #define GREP_BINARY_DEFAULT	0
     @@ revision.c: static int handle_revision_opt(struct rev_info *revs, int argc, cons
       		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
       	} else if (!strcmp(arg, "--all-match")) {
       		revs->grep_filter.all_match = 1;
     -+	// @@@ must-fix: find a better name
     -+	} else if (!strcmp(arg, "--header-or")) {
     -+		revs->grep_filter.header_or = 1;
     ++	} else if (!strcmp(arg, "--match-header-or-grep")) {
     ++		revs->grep_filter.match_header_or_grep = 1;
       	} else if (!strcmp(arg, "--invert-grep")) {
       		revs->grep_filter.no_body_match = 1;
       	} else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
     @@ t/t7810-grep.sh: test_expect_success 'log --grep --author uses intersection' '
       	test_cmp expect actual
       '
       
     -+test_expect_success 'log --grep --author --header-or uses union' '
     ++test_expect_success 'log --grep --author --match-header-or-grep uses union' '
      +	# grep matches only third and fourth
      +	# author matches only initial and third
     -+	git log --author="A U Thor" --grep=r --header-or --format=%s >actual &&
     -+	{
     -+	    echo fourth && echo third
     -+	} >expect &&
     ++	git log --author="A U Thor" --grep=r --match-header-or-grep --format=%s >actual &&
     ++	test_write_lines fourth third initial >expect &&
      +	test_cmp expect actual
      +'
     -+
      +
       test_expect_success 'log --grep --grep --author takes union of greps and intersects with author' '
       	# grep matches initial and second but not third
       	# author matches only initial and third
     +@@ t/t7810-grep.sh: test_expect_success 'log --grep --grep --author takes union of greps and interse
     + 	test_cmp expect actual
     + '
     + 
     +-test_expect_success 'log ---all-match -grep --author --author still takes union of authors and intersects with grep' '
     ++test_expect_success 'log --author --grep --grep --match-header-or-grep takes union of greps and author' '
     ++	# grep matches initial and second but not third
     ++	# author matches only initial and third
     ++	git log --author="A U Thor" --grep=second --grep=initial --match-header-or-grep --format=%s >actual &&
     ++	test_write_lines third second initial >expect &&
     ++	test_cmp expect actual
     ++'
     ++
     ++test_expect_success 'log --author --grep --grep --all-match --match-header-or-grep still takes union of greps and author' '
     ++	# grep matches initial and second but not third
     ++	# author matches only initial and third
     ++	git log --author="A U Thor" --grep=second --grep=initial --all-match --match-header-or-grep --format=%s >actual &&
     ++	test_write_lines third second initial >expect &&
     ++	test_cmp expect actual
     ++'
     ++
     ++test_expect_success 'log --all-match --grep --author --author still takes union of authors and intersects with grep' '
     + 	# grep matches only initial and third
     + 	# author matches all but second
     + 	git log --all-match --author="Thor" --author="Night" --grep=i --format=%s >actual &&

 Documentation/rev-list-options.txt     |  8 ++++++++
 contrib/completion/git-completion.bash |  2 +-
 grep.c                                 |  4 ++--
 grep.h                                 |  1 +
 revision.c                             |  2 ++
 t/t7810-grep.sh                        | 26 +++++++++++++++++++++++++-
 6 files changed, 39 insertions(+), 4 deletions(-)