[Emacs-diffs] emacs-26 0c78822: Fix subtle problem with scroll-down when scroll-margin is nonzero

[Eli Zaretskii]

branch: emacs-26
commit 0c78822c701533a94b010a043bcb049dd594bb93
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Fix subtle problem with scroll-down when scroll-margin is nonzero
    
    * src/window.c (window_scroll_pixel_based): Account for
    scroll-margin when scrolling down, i.e. moving window-start
    towards the beginning of the buffer.  Reported by zhang cc
    <address@hidden> in
    http://lists.gnu.org/archive/html/emacs-devel/2017-12/msg00894.html.
---
 src/window.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/window.c b/src/window.c
index 504dcd3..20a6020 100644
--- a/src/window.c
+++ b/src/window.c
@@ -5397,12 +5397,13 @@ window_scroll_pixel_based (Lisp_Object window, int n, 
bool whole, bool noerror)
       if (it.what == IT_EOB)
        partial_p =
          it.current_y + it.ascent + it.descent
-         > it.last_visible_y - WINDOW_HEADER_LINE_HEIGHT (w);
+         > it.last_visible_y - this_scroll_margin - WINDOW_HEADER_LINE_HEIGHT 
(w);
       else
        {
          move_it_by_lines (&it, 1);
          partial_p =
-           it.current_y > it.last_visible_y - WINDOW_HEADER_LINE_HEIGHT (w);
+           it.current_y
+           > it.last_visible_y - this_scroll_margin - 
WINDOW_HEADER_LINE_HEIGHT (w);
        }
 
       if (charpos == PT && !partial_p