(Fbuffer_swap_text): Reset window->point markers.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 70283ffb18a..f55bcd3d415 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2269,6 +2269,26 @@ DEFUN ("buffer-swap-text", Fbuffer_swap_text, Sbuffer_swap_text,
       if (m->buffer == current_buffer)
         m->buffer = other_buffer;
   }
+  { /* Some of the C code expects that w->buffer == w->pointm->buffer.
+       So since we just swapped the markers between the two buffers, we need
+       to undo the effect of this swap for window markers.  */
+    Lisp_Object w = Fselected_window (), ws = Qnil;
+    Lisp_Object buf1, buf2;
+    XSETBUFFER (buf1, current_buffer); XSETBUFFER (buf2, other_buffer);
+
+    while (NILP (Fmemq (w, ws)))
+      {
+        ws = Fcons (w, ws);
+        if (MARKERP (XWINDOW (w)->pointm)
+            && (EQ (XWINDOW (w)->buffer, buf1)
+                || EQ (XWINDOW (w)->buffer, buf2)))
+          Fset_marker (XWINDOW (w)->pointm,
+                       make_number (BUF_BEGV (XBUFFER (XWINDOW (w)->buffer))),
+                       XWINDOW (w)->buffer);
+        w = Fnext_window (w, Qt, Qt);
+      }
+  }
+
   if (current_buffer->text->intervals)
     (eassert (EQ (current_buffer->text->intervals->up.obj, buffer)),
      XSETBUFFER (current_buffer->text->intervals->up.obj, current_buffer));