(redisplay_window): When handling scroll_conservatively,

scroll a little farther for the sake of scroll_margin.

diff --git a/src/xdisp.c b/src/xdisp.c
index b74fe7243002cf98619ddbd2bdb30859e852d199..d947a5dd40a7ef8428061411b784b20674c65bed 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1822,6 +1822,15 @@ redisplay_window (window, just_this_one, preserve_echo_area)
   if (scroll_conservatively && !current_buffer->clip_changed
       && startp >= BEGV && startp <= ZV)
     {
+      int this_scroll_margin = scroll_margin;
+
+      /* Don't use a scroll margin that is negative or too large.  */
+      if (this_scroll_margin < 0)
+       this_scroll_margin = 0;
+
+      if (XINT (w->height) < 4 * scroll_margin)
+       this_scroll_margin = XINT (w->height) / 4;
+
       if (PT >= Z - XFASTINT (w->window_end_pos))
        {
          struct position pos;
@@ -1832,7 +1841,7 @@ redisplay_window (window, just_this_one, preserve_echo_area)
          if (pos.vpos > scroll_conservatively)
            goto scroll_fail_1;
 
-         pos = *vmotion (startp, pos.vpos + 1, w);
+         pos = *vmotion (startp, pos.vpos + 1 + this_scroll_margin, w);
 
          if (! NILP (Vwindow_scroll_functions))
            {
@@ -1863,7 +1872,7 @@ redisplay_window (window, just_this_one, preserve_echo_area)
          if (pos.vpos >= scroll_conservatively)
            goto scroll_fail_1;
 
-         pos = *vmotion (startp, - pos.vpos, w);
+         pos = *vmotion (startp, - pos.vpos - this_scroll_margin, w);
 
          if (! NILP (Vwindow_scroll_functions))
            {