Sortable: Skip triggering over event if it's alreay over the continer. Fixes #9041: the over event fires on every pixel movement

Author: zhizhangchen

ui/jquery.ui.sortable.js

@@ -842,8 +842,10 @@ $.widget("ui.sortable", $.ui.mouse, {
 
 		// move the item into the container if it's not there already
 		if(this.containers.length === 1) {
-			this.containers[innermostIndex]._trigger("over", event, this._uiHash(this));
-			this.containers[innermostIndex].containerCache.over = 1;
+			if (!this.containers[innermostIndex].containerCache.over) {
+				this.containers[innermostIndex]._trigger("over", event, this._uiHash(this));
+				this.containers[innermostIndex].containerCache.over = 1;
+			}
 		} else {
 
 			//When entering a new container, we will find the item with the least distance and append our item near it