bug#22586: [PATCH 1/2] Optimise ‘point in message header’ check

[Michal Nazarewicz <mina86@mina86.com>]

* lisp/gnus/message.el (message-point-in-header-p): Replace two unbound
regular expression matches with a single bound string match thus
reducing amount of work the function is doing.
---
 lisp/gnus/message.el | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/lisp/gnus/message.el b/lisp/gnus/message.el
index 77e471f..88f198f 100644
--- a/lisp/gnus/message.el
+++ b/lisp/gnus/message.el
@@ -3516,12 +3516,12 @@ message-fill-paragraph
 (defun message-point-in-header-p ()
   "Return t if point is in the header."
   (save-excursion
-    (and
-     (not
-      (re-search-backward
-       (concat "^" (regexp-quote mail-header-separator) "\n") nil t))
-     (re-search-forward
-      (concat "^" (regexp-quote mail-header-separator) "\n") nil t))))
+    (save-restriction
+      (widen)
+      (let ((bound (+ (point-at-eol) 1)) case-fold-search)
+        (goto-char (point-min))
+        (not (search-forward (concat "\n" mail-header-separator "\n")
+                             bound t))))))
 
 (defun message-do-auto-fill ()
   "Like `do-auto-fill', but don't fill in message header."
-- 
2.7.0.rc3.207.g0ac5344