[PATCH] emacs: help: bugfix

[Mark Walters]

Hi

David found a bug in the this remap/help series. He has a global
keybinding of "C-c s" for notmuch-search and this causes help in
tree-mode to hang.

I have mostly diagnosed this: the problem comes that all the construct
help routines are inside a string-match/replace-match pair. Somewhere
in these routines the match-data is being stomped on (but I have to
admit I am not sure where).

In any case putting the construct help routines inside a
save-match-data seems to fix it.

This version is a bit ugly: I am not sure of the best way to deal with
the save-match-data macro. (I think it is best to have it round
everything that happens between finding the match and replacing the
match to avoid anything similar in future).

This applies on top of the parent series.

Any comments gratefully received!

Best wishes

Mark

---
 emacs/notmuch-lib.el |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/emacs/notmuch-lib.el b/emacs/notmuch-lib.el
index 7b8acb3..e98e073 100644
--- a/emacs/notmuch-lib.el
+++ b/emacs/notmuch-lib.el
@@ -305,13 +305,16 @@ prefix argument.  PREFIX and TAIL are used internally."
 (defun notmuch-substitute-command-keys (doc)
   "Like `substitute-command-keys' but with documentation, not function names."
   (let ((beg 0))
-    (while (string-match "\\\\{\\([^}[:space:]]*\\)}" doc beg)
-      (let* ((keymap-name (substring doc (match-beginning 1) (match-end 1)))
-	     (keymap (symbol-value (intern keymap-name)))
-	     (ua-keys (where-is-internal 'universal-argument keymap t))
-	     (desc-alist (notmuch-describe-keymap keymap ua-keys keymap))
-	     (desc-list (mapcar (lambda (arg) (concat (car arg) "\t" (cdr arg))) desc-alist))
-	     (desc (mapconcat #'identity desc-list "\n")))
+    (while (string-match "\\\\{\\([^}[:space:]]*\\)}" doc beg) ;; matches \{not-space}
+      (let ((desc
+	     (save-match-data
+	       (let* ((keymap-name (substring doc (match-beginning 1) (match-end 1)))
+		      (keymap (symbol-value (intern keymap-name)))
+		      (ua-keys (where-is-internal 'universal-argument keymap t))
+		      (desc-alist (notmuch-describe-keymap keymap ua-keys keymap))
+		      (desc-list (mapcar (lambda (arg) (concat (car arg) "\t" (cdr arg))) desc-alist))
+		      (desc (mapconcat #'identity desc-list "\n")))
+		 desc))))
 	(setq doc (replace-match desc 1 1 doc)))
       (setq beg (match-end 0)))
     doc))
-- 
1.7.9.1