(js) Keep form pristine when changing passwords

Fixes #4138

NEWS

@@ -12,6 +12,7 @@ Enhancements
 Bug fixes
  - [web] fixed attachment path when inside multiple body parts
  - [web] fixed email reminder with attendees (#4115)
+ - [web] prevented form to be marked dirty when changing password (#4138)
  - [core] cherry-picked comma escaping fix from v2 (#3296)
  - [core] fix sogo-tool restore potentially crashing on corrupted data (#4048)
  - [core] handle properly mails using windows-1255 charset (#4124)

UI/Templates/PreferencesUI/UIxPreferences.wox

@@ -233,13 +233,13 @@
               <md-input-container class="md-block" flex="50">
                 <label><var:string label:value="New password"/>
                 </label>
-	        <input type="password" ng-model="app.passwords.newPassword"/>
+	        <input type="password" sg-no-dirty-check="true" ng-model="app.passwords.newPassword"/>
               </md-input-container>
 
               <md-input-container class="md-block" flex="50">
                 <label><var:string label:value="Confirmation"/>
                 </label>
-	        <input type="password" ng-model="app.passwords.newPasswordConfirmation"/>
+	        <input type="password" sg-no-dirty-check="true" ng-model="app.passwords.newPasswordConfirmation"/>
               </md-input-container>
             </div>
             <div layout="row" layout-align="end center">

UI/WebServerResources/js/Common/sgNoDirtyCheck.directive.js

@@ -0,0 +1,33 @@
+/* -*- Mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
+
+(function() {
+  'use strict';
+
+  angular
+    .module('SOGo.Common')
+    .directive('sgNoDirtyCheck', sgNoDirtyCheck);
+
+  /*
+   * sgNoDirtyCheck - prevent input from affecting the form's pristine state.
+   * @restrict attribute
+  */
+  function sgNoDirtyCheck() {
+    return {
+      restrict: 'A',
+      require: 'ngModel',
+      link: function (scope, elem, attrs, ngModelCtrl) {
+        if (!ngModelCtrl) {
+          return;
+        }
+
+        var clean = (ngModelCtrl.$pristine && !ngModelCtrl.$dirty);
+
+        if (clean) {
+          ngModelCtrl.$pristine = false;
+          ngModelCtrl.$dirty = true;
+        }
+      }
+    };
+  }
+
+})();