The make_cover_letter() function is supposed to open a new file for
writing, and let the caller write into it via FILE *rev->diffopt.file
but because the function does not return anything, the caller does not
bother checking the return value.
Make sure it dies, instead of keep going with a NULL output
filestream and relying on it to cause a crash, when it fails to
open the file.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
builtin/log.c | 2 +-
t/t4014-format-patch.sh | 6 ++++++
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/builtin/log.c b/builtin/log.c
index f2d1fbf18a..ca86611efe 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1050,7 +1050,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
if (!use_stdout &&
open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
- return;
+ die(_("failed to create cover-letter file"));
log_write_email_headers(rev, head, &pp.after_subject, &need_8bit_cte, 0);
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 909c743c13..b6e2fdbc44 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -589,6 +589,12 @@ test_expect_success 'excessive subject' '
ls patches/0004-This-is-an-excessively-long-subject-line-for-a-messa.patch
'
+test_expect_success 'failure to write cover-letter aborts gracefully' '
+ test_when_finished "rmdir 0000-cover-letter.patch" &&
+ mkdir 0000-cover-letter.patch &&
+ test_must_fail git format-patch --no-renames --cover-letter -1
+'
+
test_expect_success 'cover-letter inherits diff options' '
git mv file foo &&
git commit -m foo &&
--
2.21.0-rc2
