diff -ur xorg-server-1.19.5.orig/dix/events.c xorg-server-1.19.5/dix/events.c
--- xorg-server-1.19.5.orig/dix/events.c	2017-10-12 19:24:59.000000000 +0200
+++ xorg-server-1.19.5/dix/events.c	2018-01-27 02:01:06.564215905 +0100
@@ -863,6 +863,7 @@
             qe->pScreen = pSprite->hot.pScreen;
             ev->root_x = pSprite->hot.x;
             ev->root_y = pSprite->hot.y;
+            ev->root_x_frac = ev->root_y_frac = 0.0;
         }
     }
 #ifdef PANORAMIX
@@ -1183,6 +1184,7 @@
 
             tailev->root_x = pSprite->hotPhys.x;
             tailev->root_y = pSprite->hotPhys.y;
+            tailev->root_x_frac = tailev->root_y_frac = 0.0;
             tailev->time = event->time;
             tail->months = currentTime.months;
             return;
@@ -3055,6 +3057,7 @@
 
         ev->root_x = pSprite->hot.x;
         ev->root_y = pSprite->hot.y;
+        ev->root_x_frac = ev->root_y_frac = 0.0;
     }
 
     newSpriteWin = XYToWindow(pSprite, pSprite->hot.x, pSprite->hot.y);
diff -ur xorg-server-1.19.5.orig/dix/getevents.c xorg-server-1.19.5/dix/getevents.c
--- xorg-server-1.19.5.orig/dix/getevents.c	2017-10-12 19:24:59.000000000 +0200
+++ xorg-server-1.19.5/dix/getevents.c	2018-01-27 02:01:09.708194648 +0100
@@ -1048,10 +1048,10 @@
 static void
 event_set_root_coordinates(DeviceEvent *event, double x, double y)
 {
-    event->root_x = trunc(x);
-    event->root_y = trunc(y);
-    event->root_x_frac = x - trunc(x);
-    event->root_y_frac = y - trunc(y);
+    event->root_x = floor(x);
+    event->root_y = floor(y);
+    event->root_x_frac = x - floor(x);
+    event->root_y_frac = y - floor(y);
 }
 
 /**
diff -ur xorg-server-1.19.5.orig/Xi/exevents.c xorg-server-1.19.5/Xi/exevents.c
--- xorg-server-1.19.5.orig/Xi/exevents.c	2017-10-12 19:24:59.000000000 +0200
+++ xorg-server-1.19.5/Xi/exevents.c	2018-01-27 02:01:30.072056503 +0100
@@ -1726,6 +1726,7 @@
         GetSpritePosition(device, &rootX, &rootY);
         event->root_x = rootX;
         event->root_y = rootY;
+        event->root_x_frac = event->root_y_frac = 0.0;
         NoticeEventTime((InternalEvent *) event, device);
         event->corestate = corestate;
         key = event->detail.key;