For .show() with no arguments, only set display of elements in the second loop if they don't have style.display already set or if style.display isn't "none". Fixes #7315

Author: kswedberg

src/effects.js

@@ -36,7 +36,9 @@ jQuery.fn.extend({
 			// Set the display of most of the elements in a second loop
 			// to avoid the constant reflow
 			for ( i = 0; i < j; i++ ) {
-				this[i].style.display = jQuery.data(this[i], "olddisplay") || "";
+				if ( this[i].style.display === "" || this[i].style.display === "none" ) {
+					this[i].style.display = jQuery.data(this[i], "olddisplay") || "";
+				}
 			}
 
 			return this;

test/unit/effects.js

@@ -6,7 +6,20 @@ test("sanity check", function() {
 });
 
 test("show()", function() {
-	expect(23);
+	expect(26);
+
+	var hiddendiv = jQuery("div.hidden");
+
+	equal(jQuery.css( hiddendiv[0], "display"), "none", "hiddendiv is display: none");
+
+	hiddendiv.css("display", "block");
+	equal(jQuery.css( hiddendiv[0], "display"), "block", "hiddendiv is display: block");
+
+	hiddendiv.show();
+	equal(jQuery.css( hiddendiv[0], "display"), "block", "hiddendiv is display: block");
+
+	hiddendiv.css("display","");
+
 	var pass = true, div = jQuery("#main div");
 	div.show().each(function(){
 		if ( this.style.display == "none" ) pass = false;