Don't block changes in mouse pointer inside 'track-mouse'

* etc/NEWS:
* doc/lispref/frames.texi (Mouse Tracking): Document the special
effect of setting 'track-mouse' to 'dragging'.

* lisp/textmodes/artist.el (artist-mouse-draw-continously):
* lisp/ruler-mode.el (ruler-mode-mouse-drag-any-column-iteration):
* lisp/mouse-drag.el (mouse-drag-throw):
* lisp/mouse.el (mouse-drag-line): Set 'track-mouse' to 'dragging'
to avoid changes in the shape of the mouse pointer.

* src/xdisp.c (define_frame_cursor1): Don't change the mouse
pointer shape when do_mouse_tracking has the value of 'dragging',
not just any non-nil value.  (Bug#20934)
(syms_of_xdisp): DEFSYM 'dragging'.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 25eed01ecfc..5bef44c6e51 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -29105,7 +29105,7 @@ static void
 define_frame_cursor1 (struct frame *f, Cursor cursor, Lisp_Object pointer)
 {
   /* Do not change cursor shape while dragging mouse.  */
-  if (!NILP (do_mouse_tracking))
+  if (EQ (do_mouse_tracking, Qdragging))
     return;
 
   if (!NILP (pointer))
@@ -30727,6 +30727,8 @@ They are still logged to the *Messages* buffer.  */);
   DEFSYM (Qarrow, "arrow");
   /* also Qtext */
 
+  DEFSYM (Qdragging, "dragging");
+
   DEFSYM (Qinhibit_free_realized_faces, "inhibit-free-realized-faces");
 
   list_of_error = list1 (list2 (Qerror, Qvoid_variable));