Landing pull request 332. Appending disconnected radio or checkbox inputs and keeping checked setting Fixes #8060, #8500.

More Details:
 - https://github.com/jquery/jquery/pull/332
 - http://bugs.jquery.com/ticket/8060
 - http://bugs.jquery.com/ticket/8500

src/core.js

@@ -731,7 +731,7 @@ jQuery.extend({
 				}
 			}
 
-		// Go thorugh every key on the object,
+		// Go through every key on the object,
 		} else {
 			for ( key in elems ) {
 				value = callback( elems[ key ], key, arg );

src/manipulation.js

@@ -70,7 +70,7 @@ jQuery.fn.extend({
 				}
 
 				return elem;
-			}).append(this);
+			}).append( this );
 		}
 
 		return this;
@@ -379,13 +379,13 @@ function cloneCopyEvent( src, dest ) {
 }
 
 function cloneFixAttributes( src, dest ) {
+	var nodeName;
+
 	// We do not need to do anything for non-Elements
 	if ( dest.nodeType !== 1 ) {
 		return;
 	}
 
-	var nodeName = dest.nodeName.toLowerCase();
-
 	// clearAttributes removes the attributes, which we don't want,
 	// but also removes the attachEvent events, which we *do* want
 	if ( dest.clearAttributes ) {
@@ -398,6 +398,8 @@ function cloneFixAttributes( src, dest ) {
 		dest.mergeAttributes( src );
 	}
 
+	nodeName = dest.nodeName.toLowerCase();
+
 	// IE6-8 fail to clone children inside object elements that use
 	// the proprietary classid attribute value (rather than the type
 	// attribute) to identify the type of content to display
@@ -446,13 +448,12 @@ jQuery.buildFragment = function( args, nodes, scripts ) {
 		args[0].charAt(0) === "<" && !rnocache.test( args[0] ) && (jQuery.support.checkClone || !rchecked.test( args[0] )) ) {
 
 		cacheable = true;
+
 		cacheresults = jQuery.fragments[ args[0] ];
-		if ( cacheresults ) {
-			if ( cacheresults !== 1 ) {
+		if ( cacheresults && cacheresults !== 1 ) {
 			fragment = cacheresults;
 		}
 	}
-	}
 
 	if ( !fragment ) {
 		fragment = doc.createDocumentFragment();
@@ -508,6 +509,21 @@ function getAll( elem ) {
 	}
 }
 
+// Used in clean, fixes the defaultChecked property
+function fixDefaultChecked( elem ) {
+	if ( elem.type === "checkbox" || elem.type === "radio" ) {
+		elem.defaultChecked = elem.checked;
+	}
+}
+// Finds all inputs and passes them to fixDefaultChecked
+function findInputs( elem ) {
+	if ( jQuery.nodeName( elem, "input" ) ) {
+		fixDefaultChecked( elem );
+	} else if ( elem.getElementsByTagName ) {
+		jQuery.grep( elem.getElementsByTagName("input"), fixDefaultChecked );
+	}
+}
+
 jQuery.extend({
 	clone: function( elem, dataAndEvents, deepDataAndEvents ) {
 		var clone = elem.cloneNode(true),
@@ -578,10 +594,10 @@ jQuery.extend({
 			}
 
 			// Convert html string into DOM nodes
-			if ( typeof elem === "string" && !rhtml.test( elem ) ) {
+			if ( typeof elem === "string" ) {
+				if ( !rhtml.test( elem ) ) {
 					elem = context.createTextNode( elem );
-
-			} else if ( typeof elem === "string" ) {
+				} else {
 					// Fix "XHTML"-style tags in all browsers
 					elem = elem.replace(rxhtmlTag, "<$1></$2>");
 
@@ -617,7 +633,6 @@ jQuery.extend({
 								tbody[ j ].parentNode.removeChild( tbody[ j ] );
 							}
 						}
-
 					}
 
 					// IE completely kills leading whitespace when innerHTML is used
@@ -627,6 +642,20 @@ jQuery.extend({
 
 					elem = div.childNodes;
 				}
+			}
+
+			// Resets defaultChecked for any radios and checkboxes
+			// about to be appended to the DOM in IE 6/7 (#8060)
+			var len;
+			if ( !jQuery.support.appendChecked ) {
+				if ( elem[0] && typeof (len = elem.length) === "number" ) {
+					for ( i = 0; i < len; i++ ) {
+						findInputs( elem[i] );
+					}
+				} else {
+					findInputs( elem );
+				}
+			}
 
 			if ( elem.nodeType ) {
 				ret.push( elem );

src/support.js

@@ -186,6 +186,14 @@ jQuery.support = (function() {
 	support.reliableHiddenOffsets = isSupported && ( tds[ 0 ].offsetHeight === 0 );
 	div.innerHTML = "";
 
+	// Check if a disconnected checkbox will retain its checked
+	// value of true after appended to the DOM
+	input = document.createElement("input");
+	input.setAttribute("type", "checkbox");
+	input.checked = true;
+	div.appendChild( input );
+	support.appendChecked = input.checked;
+
 	// Check if div with explicit width and no margin-right incorrectly
 	// gets computed margin-right based on width of container. For more
 	// info see bug #3333

test/unit/manipulation.js

@@ -227,7 +227,7 @@ test("unwrap()", function() {
 });
 
 var testAppend = function(valueObj) {
-	expect(37);
+	expect(40);
 	var defaultText = "Try them out:"
 	var result = jQuery("#first").append(valueObj("<b>buga</b>"));
 	equals( result.text(), defaultText + "buga", "Check if text appending works" );
@@ -330,6 +330,20 @@ var testAppend = function(valueObj) {
 	d.contents().appendTo("#nonnodes");
 	d.remove();
 	ok( jQuery("#nonnodes").contents().length >= 2, "Check node,textnode,comment append cleanup worked" );
+
+	QUnit.reset();
+	var $input = jQuery("<input />").attr({ "type": "checkbox", "checked": true }).appendTo('#testForm');
+	equals( $input[0].checked, true, "A checked checkbox that is appended stays checked" );
+
+	QUnit.reset();
+	var $radios = jQuery("input:radio[name='R1']"),
+		$radioNot = jQuery("<input type='radio' name='R1' checked='checked'/>").insertAfter( $radios ),
+		$radio = $radios.eq(1).click();
+	$radioNot[0].checked = false;
+	$radios.parent().wrap("<div></div>");
+	equals( $radio[0].checked, true, "Reappending radios uphold which radio is checked" );
+	equals( $radioNot[0].checked, false, "Reappending radios uphold not being checked" );
+	QUnit.reset();
 }
 
 test("append(String|Element|Array&lt;Element&gt;|jQuery)", function() {