From 8aba4ca2ba15c8a1047548077d1afb36b980c88b Mon Sep 17 00:00:00 2001
From: Dzmitry Paulenka <fantasteg@gmail.com>
Date: Fri, 3 Nov 2017 16:55:26 +0300
Subject: [PATCH] Droppable: Improve over/out events detection, when greedy
 option is used

Fixes #9389
---
 tests/unit/droppable/options.js | 45 ++++++++++++++++++++++---
 ui/widgets/droppable.js         | 58 ++++++++++++++-------------------
 2 files changed, 65 insertions(+), 38 deletions(-)

diff --git a/tests/unit/droppable/options.js b/tests/unit/droppable/options.js
index 1c164495b97..a713eac37ef 100644
--- a/tests/unit/droppable/options.js
+++ b/tests/unit/droppable/options.js
@@ -79,11 +79,48 @@ QUnit.test( "scope", function( assert ) {
 	assert.equal( draggableOffset.left, oldDraggableOffset.left );
 	assert.equal( draggableOffset.top, oldDraggableOffset.top );
 } );
-/*
-Test( "greedy", function() {
-	ok(false, 'missing test - untested code is broken code');
-});
 
+QUnit.test( "greedy", function( assert ) {
+	assert.expect( 2 );
+
+	var droppableOuter = $( "<div />" )
+		.appendTo( "#qunit-fixture" )
+		.css( { position: "absolute", top: 0, left: 0, width: 20, height: 20 } )
+		.droppable( {
+			drop: function() {
+				assert.notOk( true, "outer droppable should not have drop callback called" );
+			},
+			over: function() {
+				assert.notOk( true, "outer droppable should not have over callback called" );
+			}
+		} );
+
+	$( "<div />" )
+		.appendTo( droppableOuter )
+		.css( { position: "absolute", top: 10, left: 10, width: 10, height: 10 } )
+		.droppable( {
+			greedy: true,
+			drop: function() {
+				assert.ok( true, "inner droppable should have drop callback called" );
+			},
+			over: function() {
+				assert.ok( true, "inner droppable should have over callback called" );
+			}
+		} );
+
+	//draggable is fully over inner droppable
+	var draggable = $( "<div />" )
+		.appendTo( "#qunit-fixture" )
+		.css( { position: "absolute", top: 12, left: 12, width: 5, height: 5 } )
+		.draggable();
+
+	$( draggable ).simulate( "drag", {
+		dx: 2,
+		dy: 2
+	} );
+} );
+
+/*
 test( "hoverClass", function() {
 	ok(false, 'missing test - untested code is broken code');
 });
diff --git a/ui/widgets/droppable.js b/ui/widgets/droppable.js
index 89bff2511b7..db754b718c6 100644
--- a/ui/widgets/droppable.js
+++ b/ui/widgets/droppable.js
@@ -397,52 +397,42 @@ $.ui.ddmanager = {
 		// Run through all droppables and check their positions based on specific tolerance options
 		$.each( $.ui.ddmanager.droppables[ draggable.options.scope ] || [], function() {
 
-			if ( this.options.disabled || this.greedyChild || !this.visible ) {
+			if ( this.options.disabled || !this.visible ||
+				typeof this.shouldBeOver !== "undefined" ) {
 				return;
 			}
 
-			var parentInstance, scope, parent,
-				intersects = $.ui.intersect( draggable, this, this.options.tolerance, event ),
-				c = !intersects && this.isover ?
-					"isout" :
-					( intersects && !this.isover ? "isover" : null );
-			if ( !c ) {
-				return;
-			}
+			this.shouldBeOver = $.ui.intersect( draggable, this, this.options.tolerance, event );
 
-			if ( this.options.greedy ) {
+			if ( this.options.greedy && this.shouldBeOver ) {
 
-				// find droppable parents with same scope
-				scope = this.options.scope;
-				parent = this.element.parents( ":data(ui-droppable)" ).filter( function() {
-					return $( this ).droppable( "instance" ).options.scope === scope;
+				// cancel isover for droppable parents with the same scope
+				var scope = this.options.scope;
+				this.element.parents( ":data(ui-droppable)" ).each( function() {
+					var parentInstance = $( this ).droppable( "instance" );
+					if ( parentInstance.options.scope === scope ) {
+						parentInstance.shouldBeOver = false;
+					}
 				} );
-
-				if ( parent.length ) {
-					parentInstance = $( parent[ 0 ] ).droppable( "instance" );
-					parentInstance.greedyChild = ( c === "isover" );
-				}
 			}
+		} );
 
-			// We just moved into a greedy child
-			if ( parentInstance && c === "isover" ) {
-				parentInstance.isover = false;
-				parentInstance.isout = true;
-				parentInstance._out.call( parentInstance, event );
+		// Run through all droppables and change isover status accordingly
+		$.each( $.ui.ddmanager.droppables[ draggable.options.scope ] || [], function() {
+			if ( this.options.disabled || !this.visible ) {
+				return;
 			}
 
-			this[ c ] = true;
-			this[ c === "isout" ? "isover" : "isout" ] = false;
-			this[ c === "isover" ? "_over" : "_out" ].call( this, event );
-
-			// We just moved out of a greedy child
-			if ( parentInstance && c === "isout" ) {
-				parentInstance.isout = false;
-				parentInstance.isover = true;
-				parentInstance._over.call( parentInstance, event );
+			if ( this.shouldBeOver && !this.isover ) {
+				this.isover = true;
+				this._over( event );
+			} else if ( !this.shouldBeOver && this.isover ) {
+				this.isover = false;
+				this._out( event );
 			}
-		} );
 
+			delete this.shouldBeOver;
+		} );
 	},
 	dragStop: function( draggable, event ) {
 		draggable.element.parentsUntil( "body" ).off( "scroll.droppable" );