After delete, record point location in undo.

Addresses Bug #21968.

	* lisp/simple.el (undo-auto--add-boundary): Clean up code to
	better support intercalating calls.
	* src/keyboard.c,src/keyboard.h (command_loop_1): Store value of
	point and current buffer before each command.
	* src/undo.c (record_point): Now only record the point.
	* src/undo.c (prepare_record): Functionality removed form
	record_point.
	* src/undo.c (record_delete): Check if point needs recording.
	* src/undo.c (undo-boundary): Record value of point before each
	boundary.
	* test/automated/simple-test.el: New tests.

Conflicts:
	src/undo.c

1 files changed, 33 insertions, 24 deletions

diff --git a/src/undo.c b/src/undo.c
index 060dbfc97b1..68065750b0f 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -22,10 +22,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "lisp.h"
 #include "buffer.h"
-
-/* Position of point last time we inserted a boundary.  */
-static struct buffer *last_boundary_buffer;
-static ptrdiff_t last_boundary_position;
+#include "keyboard.h"
 
 /* The first time a command records something for undo.
    it also allocates the undo-boundary object
@@ -36,36 +33,44 @@ static Lisp_Object pending_boundary;
 
 /* Record point as it was at beginning of this command (if necessary)
    and prepare the undo info for recording a change.
+/* Prepare the undo info for recording a change. */
+static void
+prepare_record ()
+{
+  /* Allocate a cons cell to be the undo boundary after this command.  */
+  if (NILP (pending_boundary))
+    pending_boundary = Fcons (Qnil, Qnil);
+
+  run_undoable_change ();
+
+  if (MODIFF <= SAVE_MODIFF)
+    record_first_change ();
+}
+
+/* Record point as it was at beginning of this command.
    PT is the position of point that will naturally occur as a result of the
    undo record that will be added just after this command terminates.  */
-
 static void
 record_point (ptrdiff_t pt)
 {
-  bool at_boundary;
-
   /* Don't record position of pt when undo_inhibit_record_point holds.  */
   if (undo_inhibit_record_point)
     return;
 
-  /* Allocate a cons cell to be the undo boundary after this command.  */
-  if (NILP (pending_boundary))
-    pending_boundary = Fcons (Qnil, Qnil);
+  bool at_boundary;
 
   at_boundary = ! CONSP (BVAR (current_buffer, undo_list))
                 || NILP (XCAR (BVAR (current_buffer, undo_list)));
 
-  if (MODIFF <= SAVE_MODIFF)
-    record_first_change ();
+  prepare_record();
 
   /* If we are just after an undo boundary, and
      point wasn't at start of deleted range, record where it was.  */
-  if (at_boundary
-      && current_buffer == last_boundary_buffer
-      && last_boundary_position != pt)
+  if (at_boundary){
     bset_undo_list (current_buffer,
-                    Fcons (make_number (last_boundary_position),
+                    Fcons (make_number (pt),
                            BVAR (current_buffer, undo_list)));
+  }
 }
 
 /* Record an insertion that just happened or is about to happen,
@@ -81,7 +86,7 @@ record_insert (ptrdiff_t beg, ptrdiff_t length)
   if (EQ (BVAR (current_buffer, undo_list), Qt))
     return;
 
-  record_point (beg);
+  prepare_record ();
 
   /* If this is following another insertion and consecutive with it
      in the buffer, combine the two.  */
@@ -153,7 +158,6 @@ record_marker_adjustments (ptrdiff_t from, ptrdiff_t to)
 /* Record that a deletion is about to take place, of the characters in
    STRING, at location BEG.  Optionally record adjustments for markers
    in the region STRING occupies in the current buffer.  */
-
 void
 record_delete (ptrdiff_t beg, Lisp_Object string, bool record_markers)
 {
@@ -162,15 +166,21 @@ record_delete (ptrdiff_t beg, Lisp_Object string, bool record_markers)
   if (EQ (BVAR (current_buffer, undo_list), Qt))
     return;
 
+  if (point_before_last_command_or_undo != beg &&
+      buffer_before_last_command_or_undo == current_buffer)
+    {
+      record_point (point_before_last_command_or_undo);
+    }
+
   if (PT == beg + SCHARS (string))
     {
       XSETINT (sbeg, -beg);
-      record_point (PT);
+      prepare_record ();
     }
   else
     {
       XSETFASTINT (sbeg, beg);
-      record_point (beg);
+      prepare_record ();
     }
 
   /* primitive-undo assumes marker adjustments are recorded
@@ -268,10 +278,11 @@ but another undo command will undo to the previous boundary.  */)
         bset_undo_list (current_buffer,
                         Fcons (Qnil, BVAR (current_buffer, undo_list)));
     }
-  last_boundary_position = PT;
-  last_boundary_buffer = current_buffer;
 
   Fset (Qundo_auto__last_boundary_cause, Qexplicit);
+  point_before_last_command_or_undo = PT;
+  buffer_before_last_command_or_undo = current_buffer;
+
   return Qnil;
 }
 
@@ -423,8 +434,6 @@ syms_of_undo (void)
   pending_boundary = Qnil;
   staticpro (&pending_boundary);
 
-  last_boundary_buffer = NULL;
-
   defsubr (&Sundo_boundary);
 
   DEFVAR_INT ("undo-limit", undo_limit,