(mouse-drag-secondary): Don't start making an overlay

when the range is empty.
(mouse-secondary-save-then-kill):
The first time, make a new kill ring entry.

diff --git a/lisp/mouse.el b/lisp/mouse.el
index f797768963444db6f2dbe7e88c14c5032465fde2..c43b25457c9528b541dbb1e79efb1f7f1b93eede 100644 (file)
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -629,11 +629,14 @@ This must be bound to a button-down mouse event."
               ;; Are we moving within the original window?
               ((and (eq (posn-window end) start-window)
                     (integer-or-marker-p end-point))
-               (set-marker mouse-secondary-start nil)
                (let ((range (mouse-start-end start-point end-point
                                              click-count)))
-                 (move-overlay mouse-secondary-overlay
-                               (car range) (nth 1 range))))
+                 (if (or (/= start-point end-point)
+                         (null (marker-position mouse-secondary-start)))
+                     (progn
+                       (set-marker mouse-secondary-start nil)
+                       (move-overlay mouse-secondary-overlay
+                                     (car range) (nth 1 range))))))
                (t
                 (let ((mouse-row (cdr (cdr (mouse-position)))))
                   (cond
@@ -787,11 +790,20 @@ again.  If you do this twice in the same position, it kills the selection."
                                      (overlay-start mouse-secondary-overlay)
                                      click-posn))
                      (setq deactivate-mark nil)))
-               (setcar kill-ring (buffer-substring
-                                  (overlay-start mouse-secondary-overlay)
-                                  (overlay-end mouse-secondary-overlay)))
-               (if interprogram-cut-function
-                   (funcall interprogram-cut-function (car kill-ring))))
+               (if (eq last-command 'mouse-secondary-save-then-kill)
+                   (progn
+                     ;; If the front of the kill ring comes from 
+                     ;; an immediately previous use of this command,
+                     ;; replace it with the extended region.
+                     ;; (It would be annoying to make a separate entry.)
+                     (setcar kill-ring
+                             (buffer-substring
+                              (overlay-start mouse-secondary-overlay)
+                              (overlay-end mouse-secondary-overlay)))
+                     (if interprogram-cut-function
+                         (funcall interprogram-cut-function (car kill-ring))))
+                 (copy-region-as-kill (overlay-start mouse-secondary-overlay)
+                                      (overlay-end mouse-secondary-overlay))))
            (if mouse-secondary-start
                ;; All we have is one end of a selection,
                ;; so put the other end here.