builtin/blame: fix leaking ignore revs files

When parsing the blame configuration we add "blame.ignoreRevsFile"
configs to a string list. This string list is declared as with `NODUP`,
and thus we hand over the allocated string to that list. We eventually
end up calling `string_list_clear()` on that list, but due to it being
declared as `NODUP` we will not release the associated strings and thus
leak memory.

Fix this issue by setting up the list as `DUP` instead and free the
config string after insertion.

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

Author: pks-t

builtin/blame.c

@@ -67,7 +67,7 @@ static int no_whole_file_rename;
 static int show_progress;
 static char repeated_meta_color[COLOR_MAXLEN];
 static int coloring_mode;
-static struct string_list ignore_revs_file_list = STRING_LIST_INIT_NODUP;
+static struct string_list ignore_revs_file_list = STRING_LIST_INIT_DUP;
 static int mark_unblamable_lines;
 static int mark_ignored_lines;
 
@@ -725,6 +725,7 @@ static int git_blame_config(const char *var, const char *value,
 		if (ret)
 			return ret;
 		string_list_insert(&ignore_revs_file_list, str);
+		free(str);
 		return 0;
 	}
 	if (!strcmp(var, "blame.markunblamablelines")) {

t/t8013-blame-ignore-revs.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='ignore revisions when blaming'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # Creates: