builtin/blame: fix leaking blame entries with --incremental

When passing `--incremental` to git-blame(1) we exit early by jumping to
the `cleanup` label. But some of the cleanups we perform are handled
between the `goto` and its label, and thus we leak the data.

Move the cleanups after the `cleanup` label. While at it, move the logic
to free the scoreboard's `final_buf` into `cleanup_scoreboard()` and
drop its `const` declaration.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

blame.c

@@ -2931,6 +2931,7 @@ void setup_blame_bloom_data(struct blame_scoreboard *sb)
 void cleanup_scoreboard(struct blame_scoreboard *sb)
 {
 	free(sb->lineno);
+	free(sb->final_buf);
 	clear_prio_queue(&sb->commits);
 	oidset_clear(&sb->ignore_list);
 

blame.h

@@ -116,7 +116,7 @@ struct blame_scoreboard {
 	 * Used by many functions to obtain contents of the nth line,
 	 * indexed with scoreboard.lineno[blame_entry.lno].
 	 */
-	const char *final_buf;
+	char *final_buf;
 	unsigned long final_buf_size;
 
 	/* linked list of blames */

builtin/blame.c

@@ -1216,12 +1216,6 @@ int cmd_blame(int argc,
 		output_option &= ~(OUTPUT_COLOR_LINE | OUTPUT_SHOW_AGE_WITH_COLOR);
 
 	output(&sb, output_option);
-	free((void *)sb.final_buf);
-	for (ent = sb.ent; ent; ) {
-		struct blame_entry *e = ent->next;
-		free(ent);
-		ent = e;
-	}
 
 	if (show_stats) {
 		printf("num read blob: %d\n", sb.num_read_blob);
@@ -1230,6 +1224,12 @@ int cmd_blame(int argc,
 	}
 
 cleanup:
+	for (ent = sb.ent; ent; ) {
+		struct blame_entry *e = ent->next;
+		free(ent);
+		ent = e;
+	}
+
 	free(path);
 	cleanup_scoreboard(&sb);
 	release_revisions(&revs);

t/t8005-blame-i18n.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='git blame encoding conversion'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 if ! test_have_prereq ICONV