On Thu, Feb 21, 2019 at 03:50:11PM -0800, Junio C Hamano wrote: > 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. Definitely makes sense. > diff --git a/builtin/log.c b/builtin/log.c > index 3e145fe502..43fc9a07df 100644 > --- a/builtin/log.c > +++ b/builtin/log.c > @@ -1047,7 +1047,7 @@ 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")); I wondered if we should be showing errno here, but it looks like open_next_file() will give us a more specific error (including errno if applicable). I'd suggest s/F/f/ in the message to match our usual style, though I see this code has a lot of capitalized errors already. :) > +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 > +' Cute test. :) -Peff