Fix bug #13055 with cursor positioning inside scroll-margin.

 src/xdisp.c (redisplay_window): If the cursor is visible, but inside
 the scroll margin, move point outside the margin.

diff --git a/src/ChangeLog b/src/ChangeLog
index f2b65db..20ed5a9 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2012-12-03  Eli Zaretskii  <eliz@gnu.org>
+
+       * xdisp.c (redisplay_window): If the cursor is visible, but inside
+       the scroll margin, move point outside the margin.  (Bug#13055)
+
 2012-12-03  Jan Djärv  <jan.h.d@swipnet.se>
 
        * gtkutil.c (my_log_handler): New function.

diff --git a/src/xdisp.c b/src/xdisp.c
index 6199c2a..5f6d69d 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -15717,6 +15717,35 @@ redisplay_window (Lisp_Object window, int just_this_one_p)
             Move it back to a fully-visible line.  */
          new_vpos = window_box_height (w);
        }
+      else if (w->cursor.vpos >=0)
+       {
+         /* Some people insist on not letting point enter the scroll
+            margin, even though this part handles windows that didn't
+            scroll at all.  */
+         struct frame *f = XFRAME (w->frame);
+         int margin = min (scroll_margin, WINDOW_TOTAL_LINES (w) / 4);
+         int pixel_margin = margin * FRAME_LINE_HEIGHT (f);
+         bool header_line = WINDOW_WANTS_HEADER_LINE_P (w);
+
+         /* Note: We add an extra FRAME_LINE_HEIGHT, because the loop
+            below, which finds the row to move point to, advances by
+            the Y coordinate of the _next_ row, see the definition of
+            MATRIX_ROW_BOTTOM_Y.  */
+         if (w->cursor.vpos < margin + header_line)
+           new_vpos
+             = pixel_margin + (header_line
+                               ? CURRENT_HEADER_LINE_HEIGHT (w)
+                               : 0) + FRAME_LINE_HEIGHT (f);
+         else
+           {
+             int window_height = window_box_height (w);
+
+             if (header_line)
+               window_height += CURRENT_HEADER_LINE_HEIGHT (w);
+             if (w->cursor.y >= window_height - pixel_margin)
+               new_vpos = window_height - pixel_margin;
+           }
+       }
 
       /* If we need to move point for either of the above reasons,
         now actually do it.  */