(record_property_change): Typo in last change.

(Fprimitive_undo): Handle property-change undo entry.
(record_property_change): New function.

1 files changed, 49 insertions, 0 deletions

diff --git a/src/undo.c b/src/undo.c
index eed355e5b10..d004410a71e 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -124,6 +124,41 @@ record_first_change ()
   current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list);
 }
 
+/* Record a change in property PROP (whose old value was VAL)
+   for LENGTH characters starting at position BEG in BUFFER.  */
+
+record_property_change (beg, length, prop, value, buffer)
+     int beg, length;
+     Lisp_Object prop, value, buffer;
+{
+  Lisp_Object lbeg, lend, entry;
+  struct buffer *obuf = current_buffer;
+  int boundary = 0;
+
+  if (!EQ (buffer, last_undo_buffer))
+    boundary = 1;
+  last_undo_buffer = buffer;
+
+  if (EQ (current_buffer->undo_list, Qt))
+    return;
+
+  /* Switch temporarily to the buffer that was changed.  */
+  current_buffer = XBUFFER (buffer);
+
+  if (boundary)
+    Fundo_boundary ();
+
+  if (MODIFF <= current_buffer->save_modified)
+    record_first_change ();
+
+  XSET (lbeg, Lisp_Int, beg);
+  XSET (lend, Lisp_Int, beg + length);
+  entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend))));
+  current_buffer->undo_list = Fcons (entry, current_buffer->undo_list);
+
+  current_buffer = obuf;
+}
+
 DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0,
   "Mark a boundary between units of undo.\n\
 An undo command will stop at this point,\n\
@@ -299,6 +334,20 @@ Return what remains of the list.")
 #endif /* CLASH_DETECTION */
                   Fset_buffer_modified_p (Qnil);
                 }
+              if (EQ (car, Qnil))
+                {
+                  /* Element (t prop val beg . end) records property change.  */
+                  Lisp_Object beg, end, prop, val;
+
+                  prop = Fcar (cdr);
+                  cdr = Fcdr (cdr);
+                  val = Fcar (cdr);
+                  cdr = Fcdr (cdr);
+                  beg = Fcar (cdr);
+                  end = Fcdr (cdr);
+
+                  Fput_text_property (beg, end, prop, val, Qnil);
+                }
               else if (XTYPE (car) == Lisp_Int && XTYPE (cdr) == Lisp_Int)
                 {
                   /* Element (BEG . END) means range was inserted.  */