fixed offset(coordinates) returns null when no matching elements in jQuery...

fixed offset(coordinates) returns null when no matching elements in jQuery object (fixes ticket #5888)

src/offset.js

@@ -2,16 +2,16 @@ if ( "getBoundingClientRect" in document.documentElement ) {
 	jQuery.fn.offset = function( options ) {
 		var elem = this[0];
 
-		if ( !elem || !elem.ownerDocument ) {
-			return null;
-		}
-
 		if ( options ) { 
 			return this.each(function( i ) {
 				jQuery.offset.setOffset( this, options, i );
 			});
 		}
 
+		if ( !elem || !elem.ownerDocument ) {
+			return null;
+		}
+
 		if ( elem === elem.ownerDocument.body ) {
 			return jQuery.offset.bodyOffset( elem );
 		}
@@ -28,16 +28,16 @@ if ( "getBoundingClientRect" in document.documentElement ) {
 	jQuery.fn.offset = function( options ) {
 		var elem = this[0];
 
-		if ( !elem || !elem.ownerDocument ) {
-			return null;
-		}
-
 		if ( options ) { 
 			return this.each(function( i ) {
 				jQuery.offset.setOffset( this, options, i );
 			});
 		}
 
+		if ( !elem || !elem.ownerDocument ) {
+			return null;
+		}
+
 		if ( elem === elem.ownerDocument.body ) {
 			return jQuery.offset.bodyOffset( elem );
 		}

test/unit/effects.js

@@ -29,9 +29,8 @@ test("show()", function() {
   	div.hide().show(speed, function() {
 			pass = false;
 		});
-		ok( pass, "Show with " + name + " does not call animate callback");
+		ok( pass, "Show with " + name + " does not call animate callback" );
 	});
-	
 
 	jQuery("#main").append('<div id="show-tests"><div><p><a href="#"></a></p><code></code><pre></pre><span></span></div><table><thead><tr><th></th></tr></thead><tbody><tr><td></td></tr></tbody></table><ul><li></li></ul></div>');
 

test/unit/offset.js

@@ -305,6 +305,13 @@ testoffset("body", function( jQuery ) {
 	equals( jQuery('body').offset().left, 1, "jQuery('#body').offset().left" );
 });
 
+test("Chaining offset(coords) returns jQuery object", function() {
+  expect(2);
+  var coords = { top:  1, left:  1 };
+	equals( jQuery("#absolute-1").offset(coords).selector, "#absolute-1", "offset(coords) returns jQuery object" );
+	equals( jQuery("#non-existent").offset(coords).selector, "#non-existent", "offset(coords) with empty jQuery set returns jQuery object" );
+});
+
 test("offsetParent", function(){
 	expect(11);