master 3c2afa6: Make `pixel-scroll-precision-scroll-up' work better with overlays

[Po Lu]

branch: master
commit 3c2afa66a217da84760849ed954245856f7e5810
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Make `pixel-scroll-precision-scroll-up' work better with overlays
    
    * lisp/pixel-scroll.el (pixel-scroll-precision-scroll-up):
    Just set vscroll when on overlay.
---
 lisp/pixel-scroll.el | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lisp/pixel-scroll.el b/lisp/pixel-scroll.el
index 4280dc2..888320c 100644
--- a/lisp/pixel-scroll.el
+++ b/lisp/pixel-scroll.el
@@ -456,9 +456,14 @@ the height of the current window."
                                                   
(window-header-line-height))))
                    (desired-start (posn-point desired-pos))
                    (desired-vscroll (cdr (posn-object-x-y desired-pos))))
-          (unless (eq (window-start) desired-start)
-            (set-window-start nil desired-start t))
-          (set-window-vscroll nil desired-vscroll t))))))
+          (let ((object (posn-object desired-pos)))
+            (if (or (consp object) (stringp object))
+                (set-window-vscroll nil (+ (window-vscroll nil t)
+                                           (- delta))
+                                    t)
+              (unless (eq (window-start) desired-start)
+                (set-window-start nil desired-start t))
+              (set-window-vscroll nil desired-vscroll t))))))))
 
 ;; FIXME: This doesn't work when there's an image above the current
 ;; line that is taller than the window.