From: Eli Zaretskii <eliz@gnu.org>
Date: Mon, 11 Apr 2011 15:59:30 +0000 (+0300)
Subject: Fix bug #8468 with redisplay when scroll-margin > 0.
X-Git-Url: http://git.hcoop.net/bpt/emacs.git/commitdiff_plain/11997c7643812a3a6f95da1c65c46d1c0307e2a7

Fix bug #8468 with redisplay when scroll-margin > 0.

 src/xdisp.c (redisplay_window): Don't try to determine the character
 position of the scroll margin if the window start point w->startp
 is outside the buffer's accessible region.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 6e9a169e8a..c164c6b5f5 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2011-04-11  Eli Zaretskii  <eliz@gnu.org>
+
+	* xdisp.c (redisplay_window): Don't try to determine the character
+	position of the scroll margin if the window start point w->startp
+	is outside the buffer's accessible region.
+
 2011-03-30  Eli Zaretskii  <eliz@gnu.org>
 
 	* xdisp.c (syms_of_xdisp) <scroll-conservatively>: Document the
diff --git a/src/xdisp.c b/src/xdisp.c
index 9e331739cd..2b032bd659 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -14248,7 +14248,14 @@ redisplay_window (Lisp_Object window, int just_this_one_p)
 
       /* If there is a scroll margin at the top of the window, find
 	 its character position.  */
-      if (margin)
+      if (margin
+	  /* Cannot call start_display if startp is not in the
+	     accessible region of the buffer.  This can happen when we
+	     have just switched to a different buffer and/or changed
+	     its restriction.  In that case, startp is initialized to
+	     the character position 1 (BEG) because we did not yet
+	     have chance to display the buffer even once.  */
+	  && BEGV <= CHARPOS (startp) && CHARPOS (startp) <= ZV)
 	{
 	  struct it it1;