From: Eli Zaretskii <eliz@gnu.org>
Date: Tue, 12 Feb 2013 16:43:09 +0000 (+0200)
Subject: Fix cursor positioning near scroll margin at top of window.
X-Git-Tag: emacs-24.3.90~173^2~7^2~71
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=c4131562319d3529841136d236ac39fb1e3d2b7c;p=emacs.git

Fix cursor positioning near scroll margin at top of window.

 src/xdisp.c (try_scrolling): Scroll text up more if point is too close
 to ZV and inside the scroll margin.  This makes sure point is moved
 outside the scroll margin in these cases.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index fb4cc723646..05737bb1194 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -6,6 +6,9 @@
 	it->region_beg_charpos, not to -1.  This fixes redisplay
 	optimization when cursor is moved up after M->.  (Bug#13623)
 	(Bug#13626)
+	(try_scrolling): Scroll text up more if point is too close to ZV
+	and inside the scroll margin.  This makes sure point is moved
+	outside the scroll margin in these cases.
 
 	* window.h (struct window): region_showing can no longer be
 	negative.
diff --git a/src/xdisp.c b/src/xdisp.c
index ca3f968afa7..d2d4b3bbb79 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -14604,14 +14604,24 @@ try_scrolling (Lisp_Object window, int just_this_one_p,
   else
     {
       struct text_pos scroll_margin_pos = startp;
+      int y_offset = 0;
 
       /* See if point is inside the scroll margin at the top of the
          window.  */
       if (this_scroll_margin)
 	{
+	  int y_start;
+
 	  start_display (&it, w, startp);
+	  y_start = it.current_y;
 	  move_it_vertically (&it, this_scroll_margin);
 	  scroll_margin_pos = it.current.pos;
+	  /* If we didn't move enough before hitting ZV, request
+	     additional amount of scroll, to move point out of the
+	     scroll margin.  */
+	  if (IT_CHARPOS (it) == ZV
+	      && it.current_y - y_start < this_scroll_margin)
+	    y_offset = this_scroll_margin - (it.current_y - y_start);
 	}
 
       if (PT < CHARPOS (scroll_margin_pos))
@@ -14638,6 +14648,9 @@ try_scrolling (Lisp_Object window, int just_this_one_p,
 	      || IT_CHARPOS (it) < CHARPOS (scroll_margin_pos))
 	    return SCROLLING_FAILED;
 
+	  /* Additional scroll for when ZV was too close to point.  */
+	  dy += y_offset;
+
 	  /* Compute new window start.  */
 	  start_display (&it, w, startp);