Change `select-active-region' mechanics.

Save region text prior to buffer modification.
Set window selection lazily, during `deactivate-mark' or after each
command when the region is temporarily active.

* lisp/cus-start.el: Add custom declaration for select-active-regions.

* lisp/mouse.el (mouse-drag-track): Remove hacks to deal with old
select-active-regions implementation.
(mouse-yank-at-click): Doc fix.

* lisp/simple.el (select-active-regions): Move to keyboard.c.
(deactivate-mark): Used saved-region-selection.
(select-active-region): Function removed.
(activate-mark, set-mark, push-mark-command)
(handle-shift-selection): Don't call it.
(keyboard-quit): Avoid adding the region to the window selection.

* src/insdel.c (prepare_to_modify_buffer): Save active region text to
Vsaved_region_selection.

* src/keyboard.c (Vselect_active_regions): Move from simple.el.
(Vsaved_region_selection, Qx_set_selection, QPRIMARY, Qlazy): New
vars.
(command_loop_1): Set window selection prior to deactivating the
mark.

* src/xselect.c (QPRIMARY): Move to keyboard.c.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/insdel.c b/src/insdel.c
index 8b0b2f7ab01..ac220d6b74b 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -74,6 +74,8 @@ Lisp_Object combine_after_change_buffer;
 
 Lisp_Object Qinhibit_modification_hooks;
 
+extern Lisp_Object Vselect_active_regions, Vsaved_region_selection;
+
 
 /* Check all markers in the current buffer, looking for something invalid.  */
 
@@ -2047,6 +2049,21 @@ prepare_to_modify_buffer (EMACS_INT start, EMACS_INT end,
 	   base_buffer->filename);
 #endif /* not CLASH_DETECTION */
 
+  /* If `select-active-regions' is non-nil, save the region text.  */
+  if (!NILP (Vselect_active_regions)
+      && !NILP (current_buffer->mark_active)
+      && !NILP (Vtransient_mark_mode)
+      && NILP (Vsaved_region_selection))
+    {
+      Lisp_Object b = Fmarker_position (current_buffer->mark);
+      Lisp_Object e = make_number (PT);
+      if (NILP (Fequal (b, e)))
+	{
+	  validate_region (&b, &e);
+	  Vsaved_region_selection = make_buffer_string (XINT (b), XINT (e), 0);
+	}
+    }
+
   signal_before_change (start, end, preserve_ptr);
 
   if (current_buffer->newline_cache)