From b0a38741df0d1ddab96f144fa58b622be5a5263c Mon Sep 17 00:00:00 2001
From: Thomas Khyn <thomas@ksytek.com>
Date: Thu, 14 Apr 2016 12:09:24 +1200
Subject: [PATCH] Mitigates rounding errors due to non-subpixel scroll values

---
 src/js/plugin/update-scroll.js | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/js/plugin/update-scroll.js b/src/js/plugin/update-scroll.js
index 40863c7..85f0e3f 100644
--- a/src/js/plugin/update-scroll.js
+++ b/src/js/plugin/update-scroll.js
@@ -52,12 +52,26 @@ module.exports = function (element, axis, value) {
   var i = instances.get(element);
 
   if (axis === 'top' && value >= i.contentHeight - i.containerHeight) {
-    element.scrollTop = value = i.contentHeight - i.containerHeight; // don't allow scroll past container
+    // don't allow scroll past container
+    value = i.contentHeight - i.containerHeight;
+    if (Math.abs(value - element.scrollTop) <= 1) {
+      // mitigates rounding errors on non-subpixel scroll values
+      value = element.scrollTop;
+    } else {
+      element.scrollTop = value;
+    }
     element.dispatchEvent(yEndEvent);
   }
 
   if (axis === 'left' && value >= i.contentWidth - i.containerWidth) {
-    element.scrollLeft = value = i.contentWidth - i.containerWidth; // don't allow scroll past container
+    // don't allow scroll past container
+    value = i.contentWidth - i.containerWidth;
+    if (Math.abs(value - element.scrollLeft) <= 1) {
+      // mitigates rounding errors on non-subpixel scroll values
+      value = element.scrollLeft;
+    } else {
+      element.scrollLeft = value;
+    }
     element.dispatchEvent(xEndEvent);
   }