[PATCH synaptics] Fix scoll increment for non-smooth scrolling (#46617)

[Peter Hutterer]

Introduced in 2603ad69b997c999404ecc441e0d64ea2cc22018. Previously, the
delta was incremented by (actual delta/scroll dist), button clicks where
then sent while (delta-- >= 1).

After 2603ad69b997c999404ecc441e0d64ea2cc22018, the delta was incremented by
the delta only, scroll dist was used as increment in the smooth scrolling
information. On non-smooth-scrolling servers, the driver would now send
too many events. Restore the old behaviour by dividing by the scroll
distance before entering the button click loop.

X.Org Bug 46617 <http://bugs.freedesktop.org/show_bug.cgi?id=46617>

Tested-by: Peter Zotov <whitequark at whitequark.org>
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/synaptics.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/src/synaptics.c b/src/synaptics.c
index 139f237..7713784 100644
--- a/src/synaptics.c
+++ b/src/synaptics.c
@@ -2743,6 +2743,12 @@ post_scroll_events(const InputInfoPtr pInfo)
     if (valuator_mask_num_valuators(priv->scroll_events_mask))
         xf86PostMotionEventM(pInfo->dev, FALSE, priv->scroll_events_mask);
 #else
+    SynapticsParameters *para = &priv->synpara;
+
+    /* smooth scrolling uses the dist as increment */
+    priv->scroll.delta_y /= para->scroll_dist_vert;
+    priv->scroll.delta_x /= para->scroll_dist_horiz;
+
     while (priv->scroll.delta_y <= -1.0)
     {
         post_button_click(pInfo, 4);
-- 
1.7.7.6