From: Chong Yidong <cyd@stupidchicken.com>
Date: Fri, 7 Nov 2008 00:29:07 +0000 (+0000)
Subject: (try_window_reusing_current_matrix): Ensure that window cursor
X-Git-Tag: emacs-pretest-23.0.90~1936
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=4a240b947eede312708308dd72c6f0e1c27d811b;p=emacs.git

(try_window_reusing_current_matrix): Ensure that window cursor
position is valid after scrolling.
---

diff --git a/src/xdisp.c b/src/xdisp.c
index 7814bac5195..ee5ecbab447 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -14393,13 +14393,6 @@ try_window_reusing_current_matrix (w)
 	if (display_line (&it))
 	  last_text_row = it.glyph_row - 1;
 
-      /* Give up If point isn't in a row displayed or reused.  */
-      if (w->cursor.vpos < 0)
-	{
-	  clear_glyph_matrix (w->desired_matrix);
-	  return 0;
-	}
-
       /* If point is in a reused row, adjust y and vpos of the cursor
 	 position.  */
       if (pt_row)
@@ -14408,6 +14401,16 @@ try_window_reusing_current_matrix (w)
 	  w->cursor.y -= first_reusable_row->y - start_row->y;
 	}
 
+      /* Give up if point isn't in a row displayed or reused.  (This
+	 also handles the case where w->cursor.vpos < nrows_scrolled
+	 after the calls to display_line, which can happen with scroll
+	 margins.  See bug#1295.)  */
+      if (w->cursor.vpos < 0)
+	{
+	  clear_glyph_matrix (w->desired_matrix);
+	  return 0;
+	}
+
       /* Scroll the display.  */
       run.current_y = first_reusable_row->y;
       run.desired_y = WINDOW_HEADER_LINE_HEIGHT (w);