(rmail-next-same-subject): Handle multiple "Re: " strings and long subject

lines that were broken into multiple lines at arbitrary places.

2 files changed, 15 insertions, 4 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 39237924e11..fc01691525f 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2005-12-10  Eli Zaretskii  <eliz@gnu.org>
+
+        * mail/rmail.el (rmail-next-same-subject): Handle multiple "Re: "
+        strings and long subject lines that were broken into multiple
+        lines at arbitrary places.
+
 2005-12-10  John W. Eaton  <jwe@octave.org>
 
         * emacs/octave-mod.el (octave-electric-space): Don't indent
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 0decf2813aa..b45467386ba 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -3155,13 +3155,18 @@ If N is negative, go backwards instead."
         search-regexp found)
     (if (string-match "\\`[ \t]+" subject)
         (setq subject (substring subject (match-end 0))))
-    (if (string-match "Re:[ \t]*" subject)
+    (if (string-match "\\`\\(Re:[ \t]*\\)+" subject)
         (setq subject (substring subject (match-end 0))))
     (if (string-match "[ \t]+\\'" subject)
         (setq subject (substring subject 0 (match-beginning 0))))
-    (setq search-regexp (concat "^Subject: *\\(Re:[ \t]*\\)?"
-                                (regexp-quote subject)
-                                "[ \t]*\n"))
+    ;; If Subject is long, mailers will break it into several lines at
+    ;; arbitrary places, so replace whitespace with a regexp that will
+    ;; match any sequence of spaces, TABs, and newlines.
+    (setq subject (regexp-quote subject))
+    (setq subject
+          (replace-regexp-in-string "[ \t\n]+" "[ \t\n]+" subject t t))
+    (setq search-regexp (concat "^Subject: *\\(Re:[ \t]*\\)*"
+                                subject "[ \t]*\n"))
     (save-excursion
       (save-restriction
         (widen)