(rmail-header-summary): Ignore letter-case of month names. (Bug#3987)

diff --git a/lisp/mail/rmailsum.el b/lisp/mail/rmailsum.el
index c35e4856f9c5893fe3921a2d3b2d0542a66d9efd..b8175c36f2340da6f64456d52036b1eb0225cf88 100644 (file)
--- a/lisp/mail/rmailsum.el
+++ b/lisp/mail/rmailsum.el
@@ -518,16 +518,19 @@ the message being processed."
    (concat (save-excursion
             (if (not (re-search-forward "^Date:" nil t))
                 "      "
-              (cond ((re-search-forward "\\([^0-9:]\\)\\([0-3]?[0-9]\\)\\([- \t_]+\\)\\([adfjmnos][aceopu][bcglnprtvy]\\)"
-                      (line-end-position) t)
+              ;; Match month names case-insensitively
+              (cond ((let ((case-fold-search t))
+                       (re-search-forward "\\([^0-9:]\\)\\([0-3]?[0-9]\\)\\([- \t_]+\\)\\([adfjmnos][aceopu][bcglnprtvy]\\)"
+                                          (line-end-position) t))
                      (format "%2d-%3s"
                              (string-to-number (buffer-substring
                                                 (match-beginning 2)
                                                 (match-end 2)))
                              (buffer-substring
                               (match-beginning 4) (match-end 4))))
-                    ((re-search-forward "\\([^a-z]\\)\\([adfjmnos][acepou][bcglnprtvy]\\)\\([-a-z \t_]*\\)\\([0-9][0-9]?\\)"
-                      (line-end-position) t)
+                    ((let ((case-fold-search t))
+                       (re-search-forward "\\([^a-z]\\)\\([adfjmnos][acepou][bcglnprtvy]\\)\\([-a-z \t_]*\\)\\([0-9][0-9]?\\)"
+                                          (line-end-position) t))
                      (format "%2d-%3s"
                              (string-to-number (buffer-substring
                                                 (match-beginning 4)