+(defun notmuch-show-move-to-current-message-summary-line ()
+ "Move to the beginning of the one-line summary of the current message.
+
+This gives us a stable place to move to and work from since the
+summary line is always visible. This is important since moving to
+an invisible location is unreliable, (the main command loop moves
+point either forward or backward to the next visible character
+when a command ends with point on an invisible character).
+
+Emits an error if point is not within a valid message, (that is
+not pattern of `notmuch-show-message-begin-regexp' could be found
+by searching backward)."
+ (beginning-of-line)
+ (if (not (looking-at notmuch-show-message-begin-regexp))
+ (if (re-search-backward notmuch-show-message-begin-regexp nil t)
+ (forward-line 2)
+ (error "Not within a valid message."))
+ (forward-line 2)))
+