(ange-ftp-file-modtime): Check a 213 response

from the server for the format we expect.  Don't use it if it
doesn't look like what the Internet draft for FTP extensions
specifies.

1 files changed, 6 insertions, 2 deletions

diff --git a/lisp/net/ange-ftp.el b/lisp/net/ange-ftp.el
index 10b03a474cf..fb2f8120c4c 100644
--- a/lisp/net/ange-ftp.el
+++ b/lisp/net/ange-ftp.el
@@ -3437,8 +3437,12 @@ Value is (0 0) if the modification time cannot be determined."
                                  (list 'quote "mdtm" (cadr (cdr parsed)))))
          (line (cdr res))
          (modtime '(0 0)))
-    (when (string-match "^213" line)
-        ;; MDTM should return "213 YYYYMMDDhhmmss" GMT on success.
+    ;; MDTM should return "213 YYYYMMDDhhmmss" GMT on success
+    ;; following the Internet draft for FTP extensions.
+    ;; Bob@rattlesnake.com reports that is returns something different
+    ;; for at least one FTP server.  So, let's use the response only
+    ;; if it matches the Internet draft.
+    (when (string-match "^213 [0-9]\\{14\\}$" line)
       (setq modtime
             (encode-time
              (string-to-number (substring line 16 18))