Merge branch 'lt/shortlog-by-committer'

"git shortlog" learned "--committer" option to group commits by
committer, instead of author.

* lt/shortlog-by-committer:
  t4201: make tests work with and without the MINGW prerequiste
  shortlog: test and document --committer option
  shortlog: group by committer information

4 files changed, 36 insertions, 3 deletions

diff --git a/Documentation/git-shortlog.txt b/Documentation/git-shortlog.txt
index 31af7f2736..ee6c5476c1 100644
--- a/Documentation/git-shortlog.txt
+++ b/Documentation/git-shortlog.txt
@@ -47,6 +47,10 @@ OPTIONS
 
 	Each pretty-printed commit will be rewrapped before it is shown.
 
+-c::
+--committer::
+	Collect and show committer identities instead of authors.
+
 -w[<width>[,<indent1>[,<indent2>]]]::
 	Linewrap the output by wrapping each line at `width`.  The first
 	line of each entry is indented by `indent1` spaces, and the second
diff --git a/builtin/shortlog.c b/builtin/shortlog.c
index ba0e1154a9..c9585d475d 100644
--- a/builtin/shortlog.c
+++ b/builtin/shortlog.c
@@ -117,11 +117,15 @@ static void read_from_stdin(struct shortlog *log)
 {
 	struct strbuf author = STRBUF_INIT;
 	struct strbuf oneline = STRBUF_INIT;
+	static const char *author_match[2] = { "Author: ", "author " };
+	static const char *committer_match[2] = { "Commit: ", "committer " };
+	const char **match;
 
+	match = log->committer ? committer_match : author_match;
 	while (strbuf_getline_lf(&author, stdin) != EOF) {
 		const char *v;
-		if (!skip_prefix(author.buf, "Author: ", &v) &&
-		    !skip_prefix(author.buf, "author ", &v))
+		if (!skip_prefix(author.buf, match[0], &v) &&
+		    !skip_prefix(author.buf, match[1], &v))
 			continue;
 		while (strbuf_getline_lf(&oneline, stdin) != EOF &&
 		       oneline.len)
@@ -140,6 +144,7 @@ void shortlog_add_commit(struct shortlog *log, struct commit *commit)
 	struct strbuf author = STRBUF_INIT;
 	struct strbuf oneline = STRBUF_INIT;
 	struct pretty_print_context ctx = {0};
+	const char *fmt;
 
 	ctx.fmt = CMIT_FMT_USERFORMAT;
 	ctx.abbrev = log->abbrev;
@@ -148,7 +153,9 @@ void shortlog_add_commit(struct shortlog *log, struct commit *commit)
 	ctx.date_mode.type = DATE_NORMAL;
 	ctx.output_encoding = get_log_output_encoding();
 
-	format_commit_message(commit, "%an <%ae>", &author, &ctx);
+	fmt = log->committer ? "%cn <%ce>" : "%an <%ae>";
+
+	format_commit_message(commit, fmt, &author, &ctx);
 	if (!log->summary) {
 		if (log->user_format)
 			pretty_print_commit(&ctx, commit, &oneline);
@@ -238,6 +245,8 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
 	int nongit = !startup_info->have_repository;
 
 	const struct option options[] = {
+		OPT_BOOL('c', "committer", &log.committer,
+			 N_("Group by committer rather than author")),
 		OPT_BOOL('n', "numbered", &log.sort_by_number,
 			 N_("sort output according to the number of commits per author")),
 		OPT_BOOL('s', "summary", &log.summary,
diff --git a/shortlog.h b/shortlog.h
index 5a326c6860..5d64cfe929 100644
--- a/shortlog.h
+++ b/shortlog.h
@@ -13,6 +13,7 @@ struct shortlog {
 	int in2;
 	int user_format;
 	int abbrev;
+	int committer;
 
 	char *common_repo_prefix;
 	int email;
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index ae08b57712..9df054bf05 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -190,4 +190,23 @@ test_expect_success 'shortlog with --output=<file>' '
 	test_line_count = 3 shortlog
 '
 
+test_expect_success 'shortlog --committer (internal)' '
+	git checkout --orphan side &&
+	git commit --allow-empty -m one &&
+	git commit --allow-empty -m two &&
+	GIT_COMMITTER_NAME="Sin Nombre" git commit --allow-empty -m three &&
+
+	cat >expect <<-\EOF &&
+	     2	C O Mitter
+	     1	Sin Nombre
+	EOF
+	git shortlog -nsc HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'shortlog --committer (external)' '
+	git log --format=full | git shortlog -nsc >actual &&
+	test_cmp expect actual
+'
+
 test_done