* simple.el (line-move-visual): If point is stuck moving backwards

against a display string, temporarily ignore the goal
column (Bug#3020).

2 files changed, 27 insertions, 16 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d8ed4e20181..e77abd01379 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,9 @@
 2009-04-25  Chong Yidong  <cyd@stupidchicken.com>
 
+        * simple.el (line-move-visual): If point is stuck moving backwards
+        against a display string, temporarily ignore the goal
+        column (Bug#3020).
+
         * startup.el (normal-top-level): Implement a work-around to handle
         changes to face-font-rescale-alist during
         initialization (Bug#1785).
diff --git a/lisp/simple.el b/lisp/simple.el
index fd281429032..082605f659d 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -4056,24 +4056,31 @@ into account variable-width characters and line continuation."
 ;; Arg says how many lines to move.  The value is t if we can move the
 ;; specified number of lines.
 (defun line-move-visual (arg &optional noerror)
-  (unless (and (floatp temporary-goal-column)
-               (or (memq last-command '(next-line previous-line))
-                   ;; In case we're called from some other command.
-                   (eq last-command this-command)))
-    (let ((posn (posn-at-point))
-          x)
+  (let ((posn (posn-at-point))
+        (opoint (point))
+        x)
+    ;; Reset temporary-goal-column, unless the previous command was a
+    ;; line-motion command or we were called from some other command.
+    (unless (and (floatp temporary-goal-column)
+                 (memq last-command `(next-line previous-line ,this-command)))
       (cond ((eq (nth 1 posn) 'right-fringe) ; overflow-newline-into-fringe
              (setq temporary-goal-column (- (window-width) 1)))
-            ((setq x (car (nth 2 posn)))
-             (setq temporary-goal-column (/ (float x) (frame-char-width)))))))
-  (or (= (vertical-motion
-          (cons (or goal-column (truncate temporary-goal-column)) arg))
-         arg)
-      (unless noerror
-        (signal (if (< arg 0)
-                    'beginning-of-buffer
-                  'end-of-buffer)
-                nil))))
+            ((setq x (car (posn-x-y posn)))
+             (setq temporary-goal-column (/ (float x) (frame-char-width))))))
+    ;; Move using `vertical-motion'.
+    (or (and (= (vertical-motion
+                 (cons (or goal-column (truncate temporary-goal-column)) arg))
+                arg)
+             (or (>= arg 0)
+                 (/= (point) opoint)
+                 ;; If the goal column lies on a display string,
+                 ;; `vertical-motion' advances the cursor to the end
+                 ;; of the string.  For arg < 0, this can cause the
+                 ;; cursor to get stuck.  (Bug#3020).
+                 (= (vertical-motion arg) arg)))
+        (unless noerror
+          (signal (if (< arg 0) 'beginning-of-buffer 'end-of-buffer)
+                  nil)))))
 
 ;; This is the guts of next-line and previous-line.
 ;; Arg says how many lines to move.