On Fri, Aug 2, 2024 at 5:32 PM Junio C Hamano <gitster@xxxxxxxxx> wrote: > > [...] > > Set `errno = 0;` prior to exiting from `strbuf_getcwd` successfully. > > This matches the behavior in functions like `run_transaction_hook` > > (refs.c:2176) and `read_ref_internal` (refs/files-backend.c:564). > > I am still uneasy to see this unconditional clearing, which looks > more like spreading the bad practice from two places you identified > than following good behaviour modelled after these two places. > > But I'll let it pass. > > As long as our programmers understand that across strbuf_getcwd(), > errno will *not* be preserved, even if the function returns success, > it would be OK. As the usual convention around errno is that a > successful call would leave errno intact, not clear it to 0, it > would make it a bit harder to learn our API for newcomers, though. For what it's worth, I share your misgivings about this change and consider the suggestion[*] to make it save/restore `errno` upon success more sensible. It would also be a welcome change to see the function documentation in strbuf.h updated to mention that it follows the usual convention of leaving `errno` untouched upon success and clobbered upon error. [*]: https://lore.kernel.org/git/xmqqv80jeza5.fsf@gitster.g/
