Merge branch 'bug7141' of http://github.com/csnover/jquery into csnover-bug7141

src/effects.js

@@ -49,9 +49,10 @@ jQuery.fn.extend({
 
 		} else {
 			for ( var i = 0, j = this.length; i < j; i++ ) {
-				var old = jQuery.data(this[i], "olddisplay");
-				if ( !old ) {
-					jQuery.data( this[i], "olddisplay", jQuery.css( this[i], "display" ) );
+				var display = jQuery.css( this[i], "display" );
+
+				if ( display !== "none" ) {
+					jQuery.data( this[i], "olddisplay", display );
 				}
 			}
 

test/unit/effects.js

@@ -770,3 +770,33 @@ test("animate with per-property easing", function(){
 	});
 
 });
+
+test("hide hidden elements (bug #7141)", function() {
+	expect(3);
+	QUnit.reset();
+
+	var div = jQuery("<div style='display:none'></div>").appendTo("#main");
+	equals( div.css("display"), "none", "Element is hidden by default" );
+	div.hide();
+	ok( !div.data("olddisplay"), "olddisplay is undefined after hiding an already-hidden element" );
+	div.show();
+	equals( div.css("display"), "block", "Show a double-hidden element" );
+
+	div.remove();
+});
+
+test("hide hidden elements, with animation (bug #7141)", function() {
+	expect(3);
+	QUnit.reset();
+	stop();
+	
+	var div = jQuery("<div style='display:none'></div>").appendTo("#main");
+	equals( div.css("display"), "none", "Element is hidden by default" );
+	div.hide(1, function () {
+		ok( !div.data("olddisplay"), "olddisplay is undefined after hiding an already-hidden element" );
+		div.show(1, function () {
+			equals( div.css("display"), "block", "Show a double-hidden element" );
+			start();
+		});
+	});
+});