From: Eli Zaretskii <eliz@gnu.org>
Date: Sun, 2 Aug 2020 15:27:33 +0000 (+0300)
Subject: Re-enable scroll-margin when cursor-motion optimization is disabled
X-Git-Tag: emacs-28.0.90~6860
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=a07ec21bf24b8d1dc41808f997dd0fb78cad3870;p=emacs.git

Re-enable scroll-margin when cursor-motion optimization is disabled

* src/xdisp.c (try_window): Fix logic of disabling margins when
cursor is close to BOB or EOB.  Account for header-line, if any,
when computing the scroll margin in pixels.  (Bug#42653)
---

diff --git a/src/xdisp.c b/src/xdisp.c
index fc17014c029..a8cd4dc853c 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -19223,18 +19223,20 @@ try_window (Lisp_Object window, struct text_pos pos, int flags)
       && !MINI_WINDOW_P (w))
     {
       int this_scroll_margin = window_scroll_margin (w, MARGIN_IN_PIXELS);
+      if (window_wants_header_line (w))
+	this_scroll_margin += CURRENT_HEADER_LINE_HEIGHT (w);
       start_display (&it, w, pos);
 
       if ((w->cursor.y >= 0	/* not vscrolled */
 	   && w->cursor.y < this_scroll_margin
-	   && CHARPOS (pos) > BEGV
-           && it_charpos < ZV)
+	   && CHARPOS (pos) > BEGV)
 	  /* rms: considering make_cursor_line_fully_visible_p here
 	     seems to give wrong results.  We don't want to recenter
 	     when the last line is partly visible, we want to allow
 	     that case to be handled in the usual way.  */
-          || w->cursor.y > (it.last_visible_y - partial_line_height (&it)
-                            - this_scroll_margin - 1))
+	  || (it_charpos < ZV	/* if EOB is visible, disable bottom margin */
+	      && w->cursor.y > (it.last_visible_y - partial_line_height (&it)
+				- this_scroll_margin - 1)))
 	{
 	  w->cursor.vpos = -1;
 	  clear_glyph_matrix (w->desired_matrix);