Use correct window reference in offset to work properly cross-frame. Fixes #6190.

src/offset.js

@@ -16,10 +16,17 @@ if ( "getBoundingClientRect" in document.documentElement ) {
 			return jQuery.offset.bodyOffset( elem );
 		}
 
-		var box = elem.getBoundingClientRect(), doc = elem.ownerDocument, body = doc.body, docElem = doc.documentElement,
-			clientTop = docElem.clientTop || body.clientTop || 0, clientLeft = docElem.clientLeft || body.clientLeft || 0,
-			top  = box.top  + (self.pageYOffset || jQuery.support.boxModel && docElem.scrollTop  || body.scrollTop ) - clientTop,
-			left = box.left + (self.pageXOffset || jQuery.support.boxModel && docElem.scrollLeft || body.scrollLeft) - clientLeft;
+		var box = elem.getBoundingClientRect(),
+			doc = elem.ownerDocument,
+			body = doc.body,
+			docElem = doc.documentElement,
+			win = getWindow(doc),
+			clientTop  = docElem.clientTop  || body.clientTop  || 0,
+			clientLeft = docElem.clientLeft || body.clientLeft || 0,
+			scrollTop  = (win.pageYOffset || jQuery.support.boxModel && docElem.scrollTop  || body.scrollTop ),
+			scrollLeft = (win.pageXOffset || jQuery.support.boxModel && docElem.scrollLeft || body.scrollLeft),
+			top  = box.top  + scrollTop  - clientTop,
+			left = box.left + scrollLeft - clientLeft;
 
 		return { top: top, left: left };
 	};

test/unit/offset.js

 module("offset");
 
+testoffset("absolute"/* in iframe */, function($, iframe) {
+	expect(4);
+	
+	var doc = iframe.document, tests;
+	
+	// force a scroll value on the main window
+	// this insures that the results will be wrong
+	// if the offset method is using the scroll offset
+	// of the parent window
+	var forceScroll = jQuery('<div>', { width: 2000, height: 2000 }).appendTo('body');
+	window.scrollTo(1, 1);
+	
+	// get offset
+	tests = [
+		{ id: '#absolute-1', top: 1, left: 1 }
+	];
+	jQuery.each( tests, function() {
+		equals( jQuery( this.id, doc ).offset().top,  this.top,  "jQuery('" + this.id + "').offset().top" );
+		equals( jQuery( this.id, doc ).offset().left, this.left, "jQuery('" + this.id + "').offset().left" );
+	});
+
+
+	// get position
+	tests = [
+		{ id: '#absolute-1', top: 0, left: 0 }
+	];
+	jQuery.each( tests, function() {
+		equals( jQuery( this.id, doc ).position().top,  this.top,  "jQuery('" + this.id + "').position().top" );
+		equals( jQuery( this.id, doc ).position().left, this.left, "jQuery('" + this.id + "').position().left" );
+	});
+	
+	forceScroll.remove();
+});
+
 testoffset("absolute", function( jQuery ) {
 	expect(144);
 	
@@ -306,8 +340,8 @@ testoffset("body", function( jQuery ) {
 });
 
 test("Chaining offset(coords) returns jQuery object", function() {
-  expect(2);
-  var coords = { top:  1, left:  1 };
+	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" );
 });