fix(select): don't support binding to select[multiple]

changing the type of select box from single to multiple or the other way around
at runtime is currently not supported and the two-way binding does odd stuff
when such situation happens.

we might eventually support this, but for now we are just going to not allow
binding to select[multiple] to prevent people from relying on something that
doesn't work.

BREAKING CHANGE: binding to select[multiple] directly or via ngMultiple (ng-multiple)
directive is not supported. This feature never worked with two-way data-binding,
so it's not expected that anybody actually depends on it.

Closes #3230

Author: IgorMinar

src/ng/compile.js

@@ -1220,6 +1220,11 @@ function $CompileProvider($provide) {
       if (!interpolateFn) return;
 
 
+      if (name === "multiple" && nodeName_(node) === "SELECT") {
+        throw new $compileMinErr("selmulti", "Binding to the multiple attribute is not supported. Element: {0}",
+            startingTag(node));
+      }
+
       directives.push({
         priority: 100,
         compile: valueFn(function attrInterpolateLinkFn(scope, element, attr) {

src/ng/directive/booleanAttrs.js

@@ -199,42 +199,6 @@
  */
 
 
-/**
- * @ngdoc directive
- * @name ng.directive:ngMultiple
- * @restrict A
- *
- * @description
- * The HTML specs do not require browsers to preserve the special attributes such as multiple.
- * (The presence of them means true and absence means false)
- * This prevents the angular compiler from correctly retrieving the binding expression.
- * To solve this problem, we introduce the `ngMultiple` directive.
- *
- * @example
-     <doc:example>
-       <doc:source>
-         Check me check multiple: <input type="checkbox" ng-model="checked"><br/>
-         <select id="select" ng-multiple="checked">
-           <option>Misko</option>
-           <option>Igor</option>
-           <option>Vojta</option>
-           <option>Di</option>
-         </select>
-       </doc:source>
-       <doc:scenario>
-         it('should toggle multiple', function() {
-           expect(element('.doc-example-live #select').prop('multiple')).toBeFalsy();
-           input('checked').check();
-           expect(element('.doc-example-live #select').prop('multiple')).toBeTruthy();
-         });
-       </doc:scenario>
-     </doc:example>
- *
- * @element SELECT
- * @param {expression} ngMultiple Angular expression that will be evaluated.
- */
-
-
 /**
  * @ngdoc directive
  * @name ng.directive:ngReadonly
@@ -334,6 +298,9 @@ var ngAttributeAliasDirectives = {};
 
 // boolean attrs are evaluated
 forEach(BOOLEAN_ATTR, function(propName, attrName) {
+  // binding to multiple is not supported
+  if (propName == "multiple") return;
+
   var normalized = directiveNormalize('ng-' + attrName);
   ngAttributeAliasDirectives[normalized] = function() {
     return {

test/ng/directive/booleanAttrsSpec.js

@@ -65,16 +65,6 @@ describe('boolean attr directives', function() {
   }));
 
 
-  it('should bind multiple', inject(function($rootScope, $compile) {
-    element = $compile('<select ng-multiple="isMultiple"></select>')($rootScope)
-    $rootScope.isMultiple=false;
-    $rootScope.$digest();
-    expect(element.attr('multiple')).toBeFalsy();
-    $rootScope.isMultiple='multiple';
-    $rootScope.$digest();
-    expect(element.attr('multiple')).toBeTruthy();
-  }));
-
   it('should bind open', inject(function($rootScope, $compile) {
     element = $compile('<details ng-open="isOpen"></details>')($rootScope)
     $rootScope.isOpen=false;
@@ -84,6 +74,30 @@ describe('boolean attr directives', function() {
     $rootScope.$digest();
     expect(element.attr('open')).toBeTruthy();
   }));
+
+
+  describe('multiple', function() {
+    it('should NOT bind to multiple via ngMultiple', inject(function($rootScope, $compile) {
+      element = $compile('<select ng-multiple="isMultiple"></select>')($rootScope)
+      $rootScope.isMultiple=false;
+      $rootScope.$digest();
+      expect(element.attr('multiple')).toBeFalsy();
+      $rootScope.isMultiple='multiple';
+      $rootScope.$digest();
+      expect(element.attr('multiple')).toBeFalsy(); // ignore
+    }));
+
+
+    it('should throw an exception if binding to multiple attribute', inject(function($rootScope, $compile) {
+      if (msie < 9) return; //IE8 doesn't support biding to boolean attributes
+
+      expect(function() {
+        $compile('<select multiple="{{isMultiple}}"></select>')
+      }).toThrow('[$compile:selmulti] Binding to the multiple attribute is not supported. ' +
+                 'Element: <select multiple="{{isMultiple}}">');
+
+    }));
+  });
 });