range-diff: avoid segfault with -I

output() reuses the same struct diff_options for multiple calls of
diff_flush().  Set the option no_free to instruct it to keep the
ignore regexes between calls and release them explicitly at the end.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/range-diff.c b/range-diff.c
index e9479794b46a51fd08b8ed287a50f35b7c92a4d5..a315c4c8894b7ed569a6af84dae7b69e5a4612f9 100644 (file)
--- a/range-diff.c
+++ b/range-diff.c
@@ -485,6 +485,7 @@ static void output(struct string_list *a, struct string_list *b,
        else
                diff_setup(&opts);
 
+       opts.no_free = 1;
        if (!opts.output_format)
                opts.output_format = DIFF_FORMAT_PATCH;
        opts.flags.suppress_diff_headers = 1;
@@ -545,6 +546,8 @@ static void output(struct string_list *a, struct string_list *b,
        strbuf_release(&buf);
        strbuf_release(&dashes);
        strbuf_release(&indent);
+       opts.no_free = 0;
+       diff_free(&opts);
 }
 
 int show_range_diff(const char *range1, const char *range2,