log: grep author/committer using mailmap

Currently you can use mailmap to display log authors and committers
but you can't use the mailmap to find commits with mapped values.

This commit allows you to run:

    git log --use-mailmap --author mapped_name_or_email
    git log --use-mailmap --committer mapped_name_or_email

Of course it only works if the --use-mailmap option is used.

The new name and email are copied only when necessary.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

revision.c

@@ -13,6 +13,7 @@
 #include "decorate.h"
 #include "log-tree.h"
 #include "string-list.h"
+#include "mailmap.h"
 
 volatile show_early_output_fn_t show_early_output;
 
@@ -2219,6 +2220,51 @@ static int rewrite_parents(struct rev_info *revs, struct commit *commit)
 	return 0;
 }
 
+static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
+{
+	char *person, *endp;
+	size_t len, namelen, maillen;
+	const char *name;
+	const char *mail;
+	struct ident_split ident;
+
+	person = strstr(buf->buf, what);
+	if (!person)
+		return 0;
+
+	person += strlen(what);
+	endp = strchr(person, '\n');
+	if (!endp)
+		return 0;
+
+	len = endp - person;
+
+	if (split_ident_line(&ident, person, len))
+		return 0;
+
+	mail = ident.mail_begin;
+	maillen = ident.mail_end - ident.mail_begin;
+	name = ident.name_begin;
+	namelen = ident.name_end - ident.name_begin;
+
+	if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
+		struct strbuf namemail = STRBUF_INIT;
+
+		strbuf_addf(&namemail, "%.*s <%.*s>",
+			    (int)namelen, name, (int)maillen, mail);
+
+		strbuf_splice(buf, ident.name_begin - buf->buf,
+			      ident.mail_end - ident.name_begin + 1,
+			      namemail.buf, namemail.len);
+
+		strbuf_release(&namemail);
+
+		return 1;
+	}
+
+	return 0;
+}
+
 static int commit_match(struct commit *commit, struct rev_info *opt)
 {
 	int retval;
@@ -2237,6 +2283,14 @@ static int commit_match(struct commit *commit, struct rev_info *opt)
 	if (buf.len)
 		strbuf_addstr(&buf, commit->buffer);
 
+	if (opt->mailmap) {
+		if (!buf.len)
+			strbuf_addstr(&buf, commit->buffer);
+
+		commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
+		commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
+	}
+
 	/* Append "fake" message parts as needed */
 	if (opt->show_notes) {
 		if (!buf.len)

t/t4203-mailmap.sh

@@ -248,11 +248,29 @@ Author: Other Author <other@author.xx>
 Author: Some Dude <some@dude.xx>
 Author: A U Thor <author@example.com>
 EOF
+
 test_expect_success 'Log output with --use-mailmap' '
 	git log --use-mailmap | grep Author >actual &&
 	test_cmp expect actual
 '
 
+cat >expect <<\EOF
+Author: Santa Claus <santa.claus@northpole.xx>
+Author: Santa Claus <santa.claus@northpole.xx>
+EOF
+
+test_expect_success 'Grep author with --use-mailmap' '
+	git log --use-mailmap --author Santa | grep Author >actual &&
+	test_cmp expect actual
+'
+
+>expect
+
+test_expect_success 'Only grep replaced author with --use-mailmap' '
+	git log --use-mailmap --author "<cto@coompany.xx>" >actual &&
+	test_cmp expect actual
+'
+
 # git blame
 cat >expect <<\EOF
 ^OBJI (A U Thor     DATE 1) one