Offset: return zeros for disconnected/hidden elements

Fixes gh-2310
Close gh-2396

src/offset.js

@@ -39,7 +39,7 @@ jQuery.offset = {
 			elem.style.position = "relative";
 		}
 
-		curOffset = curElem.offset() || { top: 0, left: 0 };
+		curOffset = curElem.offset();
 		curCSSTop = jQuery.css( elem, "top" );
 		curCSSLeft = jQuery.css( elem, "left" );
 		calculatePosition = ( position === "absolute" || position === "fixed" ) &&
@@ -110,6 +110,9 @@ jQuery.fn.extend({
 					( docElem.clientLeft || 0 )
 			};
 		}
+
+		// Return zeros for disconnected and hidden elements (gh-2310)
+		return rect;
 	},
 
 	position: function() {

test/unit/offset.js

@@ -49,30 +49,24 @@ test("empty set", function() {
 });
 
 test("disconnected element", function() {
-	expect(1);
-
-	var result;
+	expect( 2 );
 
-	try {
-		result = jQuery( document.createElement("div") ).offset();
-	} catch ( e ) {}
+	var result = jQuery( document.createElement( "div" ) ).offset();
 
-	ok( !result, "no position for disconnected element" );
+	equal( result.top, 0, "Retrieving offset on disconnected elements returns zeros (gh-2310)" );
+	equal( result.left, 0, "Retrieving offset on disconnected elements returns zeros (gh-2310)" );
 });
 
 test("hidden (display: none) element", function() {
-	expect(1);
-
-	var result,
-		node = jQuery("<div style='display: none' />").appendTo("#qunit-fixture");
+	expect( 2 );
 
-	try {
+	var node = jQuery("<div style='display: none' />").appendTo("#qunit-fixture"),
 		result = node.offset();
-	} catch ( e ) {}
 
 	node.remove();
 
-	ok( !result, "no position for hidden (display: none) element" );
+	equal( result.top, 0, "Retrieving offset on hidden elements returns zeros (gh-2310)" );
+	equal( result.left, 0, "Retrieving offset on hidden elements returns zeros (gh-2310)" );
 });
 
 testIframe("offset/absolute", "absolute", function($, iframe) {