(sendmail-send-it): If mail-from-style is parens,

don't escape all parentheses; escape only the nonmatching ones.

1 files changed, 18 insertions, 6 deletions

diff --git a/lisp/mail/sendmail.el b/lisp/mail/sendmail.el
index f30581cbb2a..f54b52cb4b5 100644
--- a/lisp/mail/sendmail.el
+++ b/lisp/mail/sendmail.el
@@ -537,12 +537,24 @@ the user from the mailer."
                                  (insert "\""))))
                          (insert " <" login ">\n"))
                         ((eq mail-from-style 'parens)
-                         (insert "From: " login " (" fullname)
-                         (let ((fullname-end (point-marker)))
-                           (backward-char (length fullname))
-                           ;; RFC 822 says ()\ must be escaped in comments.
-                           (while (re-search-forward "[()\\]" fullname-end 1)
-                             (replace-match "\\\\\\&" t)))
+                         (insert "From: " login " (")
+                         (let ((fullname-start (point)))
+                           (insert fullname)
+                           (let ((fullname-end (point-marker)))
+                             (goto-char fullname-start)
+                             ;; RFC 822 says \ and nonmatching parentheses
+                             ;; must be escaped in comments.
+                             ;; Escape every instance of ()\ ...
+                             (while (re-search-forward "[()\\]" fullname-end 1)
+                               (replace-match "\\\\\\&" t))
+                             ;; ... then undo escaping of matching parentheses,
+                             ;; including matching nested parentheses.
+                             (goto-char fullname-start)
+                             (while (re-search-forward 
+                                     "\\(\\=\\|[^\\]\\(\\\\\\\\\\)*\\)\\\\(\\(\\([^\\]\\|\\\\\\\\\\)*\\)\\\\)"
+                                     fullname-end 1)
+                               (replace-match "\\1(\\3)" t)
+                               (goto-char fullname-start))))
                          (insert ")\n"))
                         ((null mail-from-style)
                          (insert "From: " login "\n")))))