Checkboxradio: Don't re-evaluate text labels as HTML

If you generate a Checkboxradio from a checkbox/radio with a label that
contains encoded HTML, e.g. `<em>test</em>` this will work fine
at first. If, however a refresh is triggered on that instance (explicitly or
e.g. by turning it into a `Controlgroup`), the previously escaped HTML will
now be evaluated.

If the label was created based on some user input, this could lead to
unexpected code execution even though the initial output was escaped.

Fixes gh-2101
Closes gh-2102

Author: mgol

tests/unit/checkboxradio/checkboxradio.html

@@ -64,6 +64,18 @@
 <label>
 	<input type="checkbox" id="label-with-no-for"/>
 </label>
+<label>
+	<input type="checkbox" id="label-with-no-for-with-html"/>
+	<strong>Hi</strong>, <em>I'm a label</em>
+</label>
+<label>
+	<input type="checkbox" id="label-with-no-for-with-text"/>
+	Hi, I'm a label
+</label>
+<label>
+	<input type="checkbox" id="label-with-no-for-with-html-like-text"/>
+	&lt;em&gt;Hi, I'm a label&lt;/em&gt;
+</label>
 
 <form id="form3"></form>
 <input type="radio" name="crazy-form" id="crazy-form-1" form="form3" checked="checked">

tests/unit/checkboxradio/core.js

@@ -131,4 +131,41 @@ QUnit.test( "Calling checkboxradio on an input with no label throws an error", f
 	);
 } );
 
+QUnit.test( "Inheriting label from initial HTML", function( assert ) {
+	var tests = [
+		{
+			id: "label-with-no-for-with-html",
+			expectedLabel: "<strong>Hi</strong>, <em>I'm a label</em>"
+		},
+		{
+			id: "label-with-no-for-with-text",
+			expectedLabel: "Hi, I'm a label"
+		},
+		{
+			id: "label-with-no-for-with-html-like-text",
+			expectedLabel: "&lt;em&gt;Hi, I'm a label&lt;/em&gt;"
+		}
+	];
+
+	assert.expect( tests.length );
+
+	tests.forEach( function( testData ) {
+		var id = testData.id;
+		var expectedLabel = testData.expectedLabel;
+		var inputElem = $( "#" + id );
+		var labelElem = inputElem.parent();
+
+		inputElem.checkboxradio( { icon: false } );
+
+		var labelWithoutInput = labelElem.clone();
+		labelWithoutInput.find( "input" ).remove();
+
+		assert.strictEqual(
+			labelWithoutInput.html().trim(),
+			expectedLabel.trim(),
+			"Label correct [" + id + "]"
+		);
+	} );
+} );
+
 } );

tests/unit/checkboxradio/methods.js

@@ -96,4 +96,42 @@ QUnit.test( "Input wrapped in a label preserved on refresh", function( assert )
 	assert.strictEqual( input.parent()[ 0 ], element[ 0 ], "Input preserved" );
 } );
 
+QUnit.test( "Initial text label not turned to HTML on refresh", function( assert ) {
+	var tests = [
+		{
+			id: "label-with-no-for-with-html",
+			expectedLabel: "<strong>Hi</strong>, <em>I'm a label</em>"
+		},
+		{
+			id: "label-with-no-for-with-text",
+			expectedLabel: "Hi, I'm a label"
+		},
+		{
+			id: "label-with-no-for-with-html-like-text",
+			expectedLabel: "&lt;em&gt;Hi, I'm a label&lt;/em&gt;"
+		}
+	];
+
+	assert.expect( tests.length );
+
+	tests.forEach( function( testData ) {
+		var id = testData.id;
+		var expectedLabel = testData.expectedLabel;
+		var inputElem = $( "#" + id );
+		var labelElem = inputElem.parent();
+
+		inputElem.checkboxradio( { icon: false } );
+		inputElem.checkboxradio( "refresh" );
+
+		var labelWithoutInput = labelElem.clone();
+		labelWithoutInput.find( "input" ).remove();
+
+		assert.strictEqual(
+			labelWithoutInput.html().trim(),
+			expectedLabel.trim(),
+			"Label correct [" + id + "]"
+		);
+	} );
+} );
+
 } );

ui/widgets/checkboxradio.js

@@ -50,8 +50,7 @@ $.widget( "ui.checkboxradio", [ $.ui.formResetMixin, {
 	},
 
 	_getCreateOptions: function() {
-		var disabled, labels;
-		var that = this;
+		var disabled, labels, labelContents;
 		var options = this._super() || {};
 
 		// We read the type here, because it makes more sense to throw a element type error first,
@@ -71,12 +70,18 @@ $.widget( "ui.checkboxradio", [ $.ui.formResetMixin, {
 
 		// We need to get the label text but this may also need to make sure it does not contain the
 		// input itself.
-		this.label.contents().not( this.element[ 0 ] ).each( function() {
-
-			// The label contents could be text, html, or a mix. We concat each element to get a
-			// string representation of the label, without the input as part of it.
-			that.originalLabel += this.nodeType === 3 ? $( this ).text() : this.outerHTML;
-		} );
+		// The label contents could be text, html, or a mix. We wrap all elements
+		// and read the wrapper's `innerHTML` to get a string representation of
+		// the label, without the input as part of it.
+		labelContents = this.label.contents().not( this.element[ 0 ] );
+
+		if ( labelContents.length ) {
+			this.originalLabel += labelContents
+				.clone()
+				.wrapAll( "<div></div>" )
+				.parent()
+				.html();
+		}
 
 		// Set the label option if we found label text
 		if ( this.originalLabel ) {