Merge branch 'jk/read-commit-buffer-data-after-free'

"git log --grep=<pattern>" used to look for the pattern in literal
bytes of the commit log message and ignored the log-output encoding.

* jk/read-commit-buffer-data-after-free:
  log: re-encode commit messages before grepping

2 files changed, 78 insertions, 7 deletions

diff --git a/revision.c b/revision.c
index d7562ee50..ef6020541 100644
--- a/revision.c
+++ b/revision.c
@@ -2268,7 +2268,10 @@ static int commit_rewrite_person(struct strbuf *buf, const char *what, struct st
 static int commit_match(struct commit *commit, struct rev_info *opt)
 {
 	int retval;
+	const char *encoding;
+	char *message;
 	struct strbuf buf = STRBUF_INIT;
+
 	if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
 		return 1;
 
@@ -2279,13 +2282,23 @@ static int commit_match(struct commit *commit, struct rev_info *opt)
 		strbuf_addch(&buf, '\n');
 	}
 
+	/*
+	 * We grep in the user's output encoding, under the assumption that it
+	 * is the encoding they are most likely to write their grep pattern
+	 * for. In addition, it means we will match the "notes" encoding below,
+	 * so we will not end up with a buffer that has two different encodings
+	 * in it.
+	 */
+	encoding = get_log_output_encoding();
+	message = logmsg_reencode(commit, encoding);
+
 	/* Copy the commit to temporary if we are using "fake" headers */
 	if (buf.len)
-		strbuf_addstr(&buf, commit->buffer);
+		strbuf_addstr(&buf, message);
 
 	if (opt->grep_filter.header_list && opt->mailmap) {
 		if (!buf.len)
-			strbuf_addstr(&buf, commit->buffer);
+			strbuf_addstr(&buf, message);
 
 		commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
 		commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
@@ -2294,18 +2307,18 @@ static int commit_match(struct commit *commit, struct rev_info *opt)
 	/* Append "fake" message parts as needed */
 	if (opt->show_notes) {
 		if (!buf.len)
-			strbuf_addstr(&buf, commit->buffer);
-		format_display_notes(commit->object.sha1, &buf,
-				     get_log_output_encoding(), 1);
+			strbuf_addstr(&buf, message);
+		format_display_notes(commit->object.sha1, &buf, encoding, 1);
 	}
 
-	/* Find either in the commit object, or in the temporary */
+	/* Find either in the original commit message, or in the temporary */
 	if (buf.len)
 		retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
 	else
 		retval = grep_buffer(&opt->grep_filter,
-				     commit->buffer, strlen(commit->buffer));
+				     message, strlen(message));
 	strbuf_release(&buf);
+	logmsg_free(message, commit);
 	return retval;
 }
 
diff --git a/t/t4210-log-i18n.sh b/t/t4210-log-i18n.sh
new file mode 100755
index 000000000..52a74729b
--- /dev/null
+++ b/t/t4210-log-i18n.sh
@@ -0,0 +1,58 @@
+#!/bin/sh
+
+test_description='test log with i18n features'
+. ./test-lib.sh
+
+# two forms of é
+utf8_e=$(printf '\303\251')
+latin1_e=$(printf '\351')
+
+test_expect_success 'create commits in different encodings' '
+	test_tick &&
+	cat >msg <<-EOF &&
+	utf8
+
+	t${utf8_e}st
+	EOF
+	git add msg &&
+	git -c i18n.commitencoding=utf8 commit -F msg &&
+	cat >msg <<-EOF &&
+	latin1
+
+	t${latin1_e}st
+	EOF
+	git add msg &&
+	git -c i18n.commitencoding=ISO-8859-1 commit -F msg
+'
+
+test_expect_success 'log --grep searches in log output encoding (utf8)' '
+	cat >expect <<-\EOF &&
+	latin1
+	utf8
+	EOF
+	git log --encoding=utf8 --format=%s --grep=$utf8_e >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'log --grep searches in log output encoding (latin1)' '
+	cat >expect <<-\EOF &&
+	latin1
+	utf8
+	EOF
+	git log --encoding=ISO-8859-1 --format=%s --grep=$latin1_e >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'log --grep does not find non-reencoded values (utf8)' '
+	>expect &&
+	git log --encoding=utf8 --format=%s --grep=$latin1_e >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'log --grep does not find non-reencoded values (latin1)' '
+	>expect &&
+	git log --encoding=ISO-8859-1 --format=%s --grep=$utf8_e >actual &&
+	test_cmp expect actual
+'
+
+test_done