On Fri, Mar 03, 2017 at 05:06:57PM +0700, Duy Nguyen wrote: > > But if we do, I think we'd either want to: > > > > a. actually check ferror() after getting EOF and report the read > > error. That catches EISDIR, along with any other unexpected > > errors. > > > > b. use an fopen wrapper that checks fstat(fileno(fh)) after the > > open, and turns fopen(some_dir) into an error. > > If you don't like extra check, I guess you're negative on b as well > since it is an extra check on Windows. That leaves us with option a. I don't mind _doing_ the extra check that much. I don't think we fopen so many files that an extra fstat on each would kill us. I mostly just don't like having to sprinkle the explicit call to it everywhere. I'd be OK with: FILE *xfopen(const char *path, const char *mode) { FILE *ret = fopen(path, mode); #ifdef FOPEN_OPENS_DIRECTORIES if (ret) { struct stat st; if (!fstat(fileno(ret), &st) && S_ISDIR(st.st_mode)) { fclose(ret); ret = NULL; } } #endif return ret; } But I do think option (a) is cleaner. The only trick is that for errno to be valid, we need to make sure we check ferror() soon after seeing the EOF return value. I suspect it would work OK in practice for the git_config_from_file() case. -Peff