Fix inconsistency in call of readlink()

Michael Paquier · Michael Paquier · commit 1ae2feb38f1e · 2016-01-20T13:13:32.000+09:00
If the target path is too long, an error needs to be emitted as well.
The buffer is correctly null-terminated, this will just avoid running
into weird problems should the target have a too long name.
diff --git a/dir.c b/dir.c
@@ -292,11 +292,13 @@ dir_list_file_internal(parray *files, const char *root, const char *exclude[],
 		char	linked[MAXPGPATH];
 
 		len = readlink(file->path, linked, sizeof(linked));
-		if (len == -1)
-		{
+		if (len < 0)
 			elog(ERROR, "cannot read link \"%s\": %s", file->path,
 				strerror(errno));
-		}
+		if (len >= sizeof(linked))
+			elog(ERROR, "symbolic link \"%s\" target is too long\n",
+				 file->path);
+
 		linked[len] = '\0';
 		file->linked = pgut_strdup(linked);
 
