Checkboxradio: Correctly assemble radio group

Closes gh-6659
Closes gh-7082
Fixes gh-7088

js/widgets/forms/checkboxradio.js

@@ -10,12 +10,15 @@
 //>>css.theme: ../css/themes/default/jquery.mobile.theme.css
 
 define( [ "jquery",
+	"../../navigation/path",
 	"../../jquery.mobile.core",
 	"../../jquery.mobile.widget",
 	"./reset" ], function( jQuery ) {
 //>>excludeEnd("jqmBuildExclude");
 (function( $, undefined ) {
 
+var escapeId = $.mobile.path.hashToSelector;
+
 $.widget( "mobile.checkboxradio", $.extend( {
 
 	initSelector: "input:not( :jqmData(role='flipswitch' ) )[type='checkbox'],input[type='radio']:not( :jqmData(role='flipswitch' ))",
@@ -42,7 +45,7 @@ $.widget( "mobile.checkboxradio", $.extend( {
 				input
 					.closest( "form, fieldset, :jqmData(role='page'), :jqmData(role='dialog')" )
 					.find( "label" )
-					.filter( "[for='" + $.mobile.path.hashToSelector( input[0].id ) + "']" )
+					.filter( "[for='" + escapeId( input[0].id ) + "']" )
 					.first(),
 			inputtype = input[0].type,
 			checkedClass = "ui-" + inputtype + "-on",
@@ -182,14 +185,51 @@ $.widget( "mobile.checkboxradio", $.extend( {
 		});
 	},
 
-	//returns either a set of radios with the same name attribute, or a single checkbox
+	// Returns those radio buttons that are supposed to be in the same group as
+	// this radio button. In the case of a checkbox or a radio lacking a name
+	// attribute, it returns this.element.
 	_getInputSet: function() {
-		if ( this.inputtype === "checkbox" ) {
-			return this.element;
+		var selector, formId,
+			radio = this.element[ 0 ],
+			name = radio.name,
+			form = radio.form,
+			doc = radio.ownerDocument,
+
+			// A radio is always a member of its own group
+			radios = this.element;
+
+		// Only start running selectors if this is a radio button with a name
+		if ( name && this.inputtype === "radio" ) {
+			selector = "input[type='radio'][name='" + escapeId( name ) + "']";
+
+			// If we're inside a form ...
+			if ( form ) {
+				formId = form.id;
+
+				// ... and the form has an ID, collect radios scattered throught the document which
+				// nevertheless are part of the form by way of the value of their form attribute
+				if ( formId ) {
+					radios = $( selector + "[form='" + escapeId( formId ) + "']", doc );
+				}
+
+				// ... and add to those the radios in the form itself
+				radios = $( form ).find( selector ).filter( function() {
+
+					// ... but some radios inside the form may belong to some other form by virtue
+					// of having a form attribute defined on them, so we must filter them out here
+					return ( this.form === form );
+				}).add( radios );
+
+			// Otherwise, if we're outside a form ...
+			} else {
+
+				// ... collect all those radios which are also outside of a form and match our name
+				radios = $( selector, doc ).filter( function() {
+					return !this.form;
+				});
+			}
 		}
-
-		return this.element.closest( "form, :jqmData(role='page'), :jqmData(role='dialog')" )
-			.find( "input[name='" + this.element[ 0 ].name + "'][type='" + this.inputtype + "']" );
+		return radios;
 	},
 
 	_updateAll: function() {