From 695358983e58c9f3d0c6b755ce89fa92adbea0ea Mon Sep 17 00:00:00 2001
From: TJ VanToll <tj.vantoll@gmail.com>
Date: Fri, 28 Dec 2012 22:17:50 -0500
Subject: [PATCH] Selectable: Account for scrolling on the helper's initial
 position. Fixed #8915 - Selectable: Lasso offset issue with scrolling.

---
 tests/unit/selectable/selectable_events.js | 28 ++++++++++++++++++++++
 ui/jquery.ui.selectable.js                 |  4 ++--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/tests/unit/selectable/selectable_events.js b/tests/unit/selectable/selectable_events.js
index 984fd1862..f933d3890 100644
--- a/tests/unit/selectable/selectable_events.js
+++ b/tests/unit/selectable/selectable_events.js
@@ -35,4 +35,32 @@ test( "stop", function() {
 	});
 });
 
+test( "mousedown: initial position of helper", function() {
+	expect( 2 );
+
+	var contentToForceScroll, helper,
+		element = $("#selectable1").selectable();
+
+	contentToForceScroll = $("<div>").css({
+		height: "10000px",
+		width: "10000px"
+	});
+
+	contentToForceScroll.appendTo("body");
+	$( window ).scrollTop( 1 ).scrollLeft( 1 );
+	element.simulate( "mousedown", {
+		clientX: 10,
+		clientY: 10
+	});
+
+	helper = $(".ui-selectable-helper");
+	equal( helper.css("top"), "11px", "Scroll top should be accounted for." );
+	equal( helper.css("left"), "11px", "Scroll left should be accounted for." );
+
+	// Cleanup
+	element.simulate("mouseup");
+	contentToForceScroll.remove();
+	$( window ).scrollTop( 0 ).scrollLeft( 0 );
+});
+
 })( jQuery );
diff --git a/ui/jquery.ui.selectable.js b/ui/jquery.ui.selectable.js
index 32152291b..8e6d03c1f 100644
--- a/ui/jquery.ui.selectable.js
+++ b/ui/jquery.ui.selectable.js
@@ -88,8 +88,8 @@ $.widget("ui.selectable", $.ui.mouse, {
 		$(options.appendTo).append(this.helper);
 		// position helper (lasso)
 		this.helper.css({
-			"left": event.clientX,
-			"top": event.clientY,
+			"left": event.pageX,
+			"top": event.pageY,
 			"width": 0,
 			"height": 0
 		});
-- 
2.39.5