Undo in region after markers in undo history relocated

* simple.el (primitive-undo): Only process marker adjustments
validated against their corresponding (TEXT . POS).  Issue warning
for lone marker adjustments in undo history.  (Bug#16818)
(undo-make-selective-list): Add marker adjustments to selective
undo list based on whether their corresponding (TEXT . POS) is in
the region.  Remove variable adjusted-markers, which was unused
and only non nil during undo-make-selective-list.
(undo-elt-in-region): Return nil when passed a marker adjustment
and explain in function doc.

Have (MARKER . ADJUSTMENT) undo records always be immediately
after their corresponding (TEXT . POS) record in undo list.
(Bug#16818)
* lisp.h (record-delete): New arg record_markers.
(record_marker_adjustment): No longer needed outside undo.c.
* insdel.c (adjust_markers_for_delete): Move calculation of marker
adjustments to undo.c's record_marker_adjustments.  Note that
fileio.c's decide_coding_unwind is another caller to
adjust_markers_for_delete.  Because it has undo list bound to t,
it does not rely on adjust_markers_for_delete to record marker
adjustments.
(del_range_2): Swap call to record_delete and
adjust_markers_for_delete so as undo marker adjustments are
recorded before current deletion's adjustments, as before.
(adjust_after_replace):
(replace_range): Pass value for new record_markers arg to
delete_record.
* undo.c (record_marker_adjustment): Renamed to
record_marker_adjustments and made static.
(record_delete): Check record_markers arg and call
record_marker_adjustments.
(record_change): Pass value for new record_markers arg to
delete_record.
(record_point): at_boundary calculation no longer needs to account
for marker adjustments.

* undo-tests.el (undo-test-marker-adjustment-nominal):
(undo-test-region-t-marker): New tests of marker adjustments.
(undo-test-marker-adjustment-moved):
(undo-test-region-mark-adjustment): New tests to demonstrate
bug#16818, which fail without the fix.

* markers.texi (Moving Marker Positions): The 2014-03-02 doc
change mentioning undo's inability to handle relocated markers no
longer applies.  See bug#16818.
* text.texi (Undo): Expand documentation of (TEXT . POS) and
(MARKER . ADJUSTMENT) undo elements.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index da82eca9df2..cbe10d89690 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,31 @@
+2014-03-24  Barry O'Reilly  <gundaetiapo@gmail.com>
+
+        Have (MARKER . ADJUSTMENT) undo records always be immediately
+        after their corresponding (TEXT . POS) record in undo list.
+        (Bug#16818)
+        * lisp.h (record-delete): New arg record_markers.
+        (record_marker_adjustment): No longer needed outside undo.c.
+        * insdel.c (adjust_markers_for_delete): Move calculation of marker
+        adjustments to undo.c's record_marker_adjustments.  Note that
+        fileio.c's decide_coding_unwind is another caller to
+        adjust_markers_for_delete.  Because it has undo list bound to t,
+        it does not rely on adjust_markers_for_delete to record marker
+        adjustments.
+        (del_range_2): Swap call to record_delete and
+        adjust_markers_for_delete so as undo marker adjustments are
+        recorded before current deletion's adjustments, as before.
+        (adjust_after_replace):
+        (replace_range): Pass value for new record_markers arg to
+        delete_record.
+        * undo.c (record_marker_adjustment): Renamed to
+        record_marker_adjustments and made static.
+        (record_delete): Check record_markers arg and call
+        record_marker_adjustments.
+        (record_change): Pass value for new record_markers arg to
+        delete_record.
+        (record_point): at_boundary calculation no longer needs to account
+        for marker adjustments.
+
 2014-03-24  Martin Rudalics  <rudalics@gmx.at>
 
         * w32term.c (x_set_window_size): Refine fix from 2014-03-14