entry: check for fstat() errors after checkout

matheustavares · gitster · commit 35e6e212fdea · 2020-07-09T09:45:06.000-07:00
In 11179eb ("entry.c: check if file exists after checkout", 2017-10-05) we started checking the result of the lstat() call done after writing a file, to avoid writing garbage to the corresponding cache entry. However, the code skips calling lstat() if it's possible to use fstat() when it still has the file descriptor open. And when calling fstat() we don't do the same error checking. To fix that, let the callers of fstat_output() know when fstat() fails. In this case, write_entry() will try to use lstat() and properly report an error if that fails as well. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/entry.c b/entry.c
@@ -113,8 +113,7 @@ static int fstat_output(int fd, const struct checkout *state, struct stat *st)
 	/* use fstat() only when path == ce->name */
 	if (fstat_is_reliable() &&
 	    state->refresh_cache && !state->base_dir_len) {
-		fstat(fd, st);
-		return 1;
+		return !fstat(fd, st);
 	}
 	return 0;
 }

Original file line number	Diff line number	Diff line change
`@@ -113,8 +113,7 @@ static int fstat_output(int fd, const struct checkout state, struct stat st)`
`113`	`113`	`/* use fstat() only when path == ce->name */`
`114`	`114`	`if (fstat_is_reliable() &&`
`115`	`115`	`state->refresh_cache && !state->base_dir_len) {`
`116`		`- fstat(fd, st);`
`117`		`- return 1;`
	`116`	`+ return !fstat(fd, st);`
`118`	`117`	`}`
`119`	`118`	`return 0;`
`120`	`119`	`}`