Improve pg_check_dir's handling of closedir() failures.

robertmhaas · robertmhaas · commit d7d294f5935e · 2015-02-17T11:08:40.000-05:00
Avoid losing errno if readdir() fails and closedir() works. This also avoids leaking the directory handle when readdir() fails. Commit 6f03927 introduced logic to better handle readdir() and closedir() failures, bu it missed these cases. Extracted from a larger patch by Marco Nenciarini.
diff --git a/src/port/pgcheckdir.c b/src/port/pgcheckdir.c
@@ -31,6 +31,7 @@ pg_check_dir(const char *dir)
 	int			result = 1;
 	DIR		   *chkdir;
 	struct dirent *file;
+	int			readdir_errno;
 
 	chkdir = opendir(dir);
 
@@ -58,8 +59,15 @@ pg_check_dir(const char *dir)
 		errno = 0;
 #endif
 
-	if (errno || closedir(chkdir))
+	if (errno)
 		result = -1;			/* some kind of I/O error? */
 
+	/* Close chkdir and avoid overwriting the readdir errno on success */
+	readdir_errno = errno;
+	if (closedir(chkdir))
+		result = -1;			/* error executing closedir */
+	else
+		errno = readdir_errno;
+
 	return result;
 }
