combine-diff: abort if --output is given
The code for combined diffs currently only writes to stdout. Abort and
report that fact instead of silently ignoring the --output option. The
(empty) output file has already been created at that point, though.
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/combine-diff.c b/combine-diff.c
index 512897e..76d2351 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -1501,6 +1501,9 @@ void diff_tree_combined(const struct object_id *oid,
if (opt->ignore_regex_nr)
die("combined diff and '%s' cannot be used together",
"--ignore-matching-lines");
+ if (opt->close_file)
+ die("combined diff and '%s' cannot be used together",
+ "--output");
/* nothing to do, if no parents */
if (!num_parent)
