emacs: Fix `notmuch-show-rewind' in the presence of invisible text

When determining whether or not to re-align the head of the current
message with the top of the window, use `count-screen-lines' rather
than `count-lines' to allow for invisible text in the preceding
message. When comparing that number of lines against
`next-screen-context-lines', realign if the number of lines of the
previous message visible is 'smaller than or equal to' rather than
just 'smaller than' to improve usability.

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index f5de8ae91a79fdf8679b2b6b13e2776ad208a6a8..eb5335ff2f7f918865d7681fc18a50510e7abce0 100644 (file)
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -833,8 +833,8 @@ any effects from previous calls to
       ;; If a small number of lines from the previous message are
       ;; visible, realign so that the top of the current message is at
       ;; the top of the screen.
-      (if (< (count-lines (window-start) (notmuch-show-message-top))
-            next-screen-context-lines)
+      (if (<= (count-screen-lines (window-start) start-of-message)
+             next-screen-context-lines)
          (progn
            (goto-char (notmuch-show-message-top))
            (notmuch-show-message-adjust)))