Fix bugs #13623 and 13626 caused by changes in 2013-02-01T07:23:18Z!dmantipov@yandex.ru.

 src/xdisp.c (window_buffer_changed): region_showing can be negative,
 which still means region is being displayed.
 (redisplay_internal): Resurrect code that forced redisplay of the
 whole window when showing region and the mark has changed.  Record
 the new mark position to allow redisplay optimizations.
 (display_line): If it->region_beg_charpos is non-zero, set the
 window's region_showing member to -1.
 src/window.h (struct window) <region_showing>: Declare ptrdiff_t,
 not bitfield of 1 bit.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/window.h b/src/window.h
index f28ce1424d0..0f4f242641e 100644
--- a/src/window.h
+++ b/src/window.h
@@ -333,13 +333,15 @@ struct window
        the frame image that window_end_pos did not get onto the frame.  */
     unsigned window_end_valid : 1;
 
-    /* Nonzero if we have highlighted the region (or any part of it).  */
-    unsigned region_showing : 1;
-
     /* Amount by which lines of this window are scrolled in
        y-direction (smooth scrolling).  */
     int vscroll;
 
+    /* If we have highlighted the region (or any part of it), the mark
+       position or -1 (the latter is used by the iterator for internal
+       purposes); otherwise zero.  */
+    ptrdiff_t region_showing;
+
     /* Z_BYTE - buffer position of the last glyph in the current matrix of W.
        Should be nonnegative, and only valid if window_end_valid is nonzero.  */
     ptrdiff_t window_end_bytepos;