notmuch.el: Override next-line and previous-line to make them reliable.

I noticed that these functions would sometimes leave point on an
invisible character[*]. The problem would be that point would appear
to be on a particular message, but adding or removing a tag would
actually add/remove a tag from the *previous* message.

Fix the C-n and C-p keybindings at least to call the underlying
command and then advance to a visible character. We set this-command
in our overrides so that the temporary-goal-column feature still
works.

[*] The documentation says that command loop is supposed to move point
outside of any invisible region when a command exits. But apparently
not.

diff --git a/notmuch.el b/notmuch.el
index 54237f128441503c774fa3938012144274095065..a205267ecfed76df05c04ef0861c7999f373c849 100644 (file)
--- a/notmuch.el
+++ b/notmuch.el
@@ -34,6 +34,8 @@
     (define-key map "h" 'notmuch-show-toggle-headers-visible)
     (define-key map "n" 'notmuch-show-next-message)
     (define-key map "p" 'notmuch-show-previous-message)
+    (define-key map (kbd "C-n") 'notmuch-show-next-line)
+    (define-key map (kbd "C-p") 'notmuch-show-previous-line)
     (define-key map "q" 'kill-this-buffer)
     (define-key map "s" 'notmuch-show-toggle-signatures-visible)
     (define-key map "x" 'kill-this-buffer)
@@ -73,6 +75,30 @@ within the current window."
       (or (memq prop buffer-invisibility-spec)
          (assq prop buffer-invisibility-spec)))))
 
+(defun notmuch-show-next-line ()
+  "Like builtin `next-line' but ensuring we end on a visible character.
+
+By advancing forward until reaching a visible character.
+
+Unlike builtin `next-line' this version accepts no arguments."
+  (interactive)
+  (set 'this-command 'next-line)
+  (call-interactively 'next-line)
+  (while (point-invisible-p)
+    (forward-char)))
+
+(defun notmuch-show-previous-line ()
+  "Like builtin `previous-line' but ensuring we end on a visible character.
+
+By advancing forward until reaching a visible character.
+
+Unlike builtin `next-line' this version accepts no arguments."
+  (interactive)
+  (set 'this-command 'previous-line)
+  (call-interactively 'previous-line)
+  (while (point-invisible-p)
+    (forward-char)))
+
 (defun notmuch-show-get-message-id ()
   (save-excursion
     (beginning-of-line)