Fix + tests for disabled control

onKeyDown was checking the state, not props, for disabled
This didn't affect the normal operation, as the control
was not focusable when disabled, but could have potentially
caused issues in certain browsers

src/Select.js

@@ -381,7 +381,7 @@ var Select = React.createClass({
 	},
 
 	handleKeyDown: function(event) {
-		if (this.state.disabled) return;
+		if (this.props.disabled) return;
 
 		switch (event.keyCode) {
 

test/Select-test.js

@@ -826,8 +826,12 @@ describe('Select', function() {
 			);
 
 			// Focus on the input, such that mouse events are accepted
-			searchInputNode = React.findDOMNode(instance.getInputNode()).querySelector('input');
-			TestUtils.Simulate.focus(searchInputNode);
+			var searchInstance = React.findDOMNode(instance.getInputNode());
+			searchInputNode = null;
+			if (searchInstance) {
+				searchInputNode = searchInstance.querySelector('input');
+				TestUtils.Simulate.focus(searchInputNode);
+			}
 			return instance;
 
 		};
@@ -1098,5 +1102,46 @@ describe('Select', function() {
 				});
 			});
 		});
+
+		describe('disabled=true', function () {
+
+			beforeEach(function () {
+
+				instance = createControl({
+					options: defaultOptions,
+					value: 'three',
+					disabled: true,
+					searchable: true
+				});
+			});
+
+			it('does not render an input search control', function () {
+
+				expect(searchInputNode, 'to be null');
+			});
+
+			it('does not react to keyDown', function () {
+
+				TestUtils.Simulate.keyDown(getSelectControl(instance), { keyCode: 40, key: 'ArrowDown' });
+				expect(React.findDOMNode(instance).querySelectorAll('.Select-option'), 'to have length', 0);
+			});
+
+			it('does not respond to mouseDown', function () {
+
+				TestUtils.Simulate.mouseDown(getSelectControl(instance));
+				expect(React.findDOMNode(instance).querySelectorAll('.Select-option'), 'to have length', 0);
+			});
+
+			it('does not respond to mouseDown on the arrow', function () {
+
+				TestUtils.Simulate.mouseDown(getSelectControl(instance).querySelector('.Select-arrow'));
+				expect(React.findDOMNode(instance).querySelectorAll('.Select-option'), 'to have length', 0);
+			});
+
+			it('renders the given value', function () {
+
+				expect(React.findDOMNode(instance).querySelector(DISPLAYED_SELECTION_SELECTOR), 'to have text', 'Three');
+			});
+		});
 	});
 });