Persist login instructions onto flow-specific login pages (username/password and LDAP)

Summary:
Fixes T13433. Currently, "Login Screen Instructions" in "Auth" are shown only on the main login screen. If you enter a bad password or bad LDAP credential set and move to the flow-specific login failure screen (for example, "invalid password"), the instructions vanish.

Instead, persist them. There are reasonable cases where this is highly useful and the cases which spring to mind where this is possibly misleading are fairly easy to fix by making the instructions more specific.

Test Plan:
  - Configured login instructions in "Auth".
  - Viewed main login screen, saw instructions.
  - Entered a bad username/password and a bad LDAP credential set, got kicked to workflow sub-pages and still saw instructions (previously: no instructions).
  - Grepped for other callers to `buildProviderPageResponse()` to look for anything weird, came up empty.

Maniphest Tasks: T13433

Differential Revision: https://secure.phabricator.com/D20863

resources/celerity/map.php

@@ -9,7 +9,7 @@ return array(
   'names' => array(
     'conpherence.pkg.css' => '3c8a0668',
     'conpherence.pkg.js' => '020aebcf',
-    'core.pkg.css' => '88366522',
+    'core.pkg.css' => '686ae87c',
     'core.pkg.js' => '6e5c894f',
     'differential.pkg.css' => '607c84be',
     'differential.pkg.js' => 'a0212a0b',
@@ -36,7 +36,7 @@ return array(
     'rsrc/css/aphront/typeahead-browse.css' => 'b7ed02d2',
     'rsrc/css/aphront/typeahead.css' => '8779483d',
     'rsrc/css/application/almanac/almanac.css' => '2e050f4f',
-    'rsrc/css/application/auth/auth.css' => 'add92fd8',
+    'rsrc/css/application/auth/auth.css' => 'c2f23d74',
     'rsrc/css/application/base/main-menu-view.css' => '17b71bbc',
     'rsrc/css/application/base/notification-menu.css' => '4df1ee30',
     'rsrc/css/application/base/phui-theme.css' => '35883b37',
@@ -540,7 +540,7 @@ return array(
     'aphront-tooltip-css' => 'e3f2412f',
     'aphront-typeahead-control-css' => '8779483d',
     'application-search-view-css' => '0f7c06d8',
-    'auth-css' => 'add92fd8',
+    'auth-css' => 'c2f23d74',
     'bulk-job-css' => '73af99f5',
     'conduit-api-css' => 'ce2cfc41',
     'config-options-css' => '16c920ae',

src/applications/auth/controller/PhabricatorAuthController.php

@@ -286,4 +286,26 @@ abstract class PhabricatorAuthController extends PhabricatorController {
       ->appendChild($invite_list);
   }
 
+
+  final protected function newCustomStartMessage() {
+    $viewer = $this->getViewer();
+
+    $text = PhabricatorAuthMessage::loadMessageText(
+      $viewer,
+      PhabricatorAuthLoginMessageType::MESSAGEKEY);
+
+    if (!strlen($text)) {
+      return null;
+    }
+
+    $remarkup_view = new PHUIRemarkupView($viewer, $text);
+
+    return phutil_tag(
+      'div',
+      array(
+        'class' => 'auth-custom-message',
+      ),
+      $remarkup_view);
+  }
+
 }

src/applications/auth/controller/PhabricatorAuthLoginController.php

@@ -238,18 +238,24 @@ final class PhabricatorAuthLoginController
     $content) {
 
     $crumbs = $this->buildApplicationCrumbs();
+    $viewer = $this->getViewer();
 
-    if ($this->getRequest()->getUser()->isLoggedIn()) {
+    if ($viewer->isLoggedIn()) {
       $crumbs->addTextCrumb(pht('Link Account'), $provider->getSettingsURI());
     } else {
-      $crumbs->addTextCrumb(pht('Log In'), $this->getApplicationURI('start/'));
+      $crumbs->addTextCrumb(pht('Login'), $this->getApplicationURI('start/'));
+
+      $content = array(
+        $this->newCustomStartMessage(),
+        $content,
+      );
     }
 
     $crumbs->addTextCrumb($provider->getProviderName());
     $crumbs->setBorder(true);
 
     return $this->newPage()
-      ->setTitle(pht('Log In'))
+      ->setTitle(pht('Login'))
       ->setCrumbs($crumbs)
       ->appendChild($content);
   }

src/applications/auth/controller/PhabricatorAuthStartController.php

@@ -298,27 +298,6 @@ final class PhabricatorAuthStartController
       ->setURI($auto_uri);
   }
 
-  private function newCustomStartMessage() {
-    $viewer = $this->getViewer();
-
-    $text = PhabricatorAuthMessage::loadMessageText(
-      $viewer,
-      PhabricatorAuthLoginMessageType::MESSAGEKEY);
-
-    if (!strlen($text)) {
-      return null;
-    }
-
-    $remarkup_view = new PHUIRemarkupView($viewer, $text);
-
-    return phutil_tag(
-      'div',
-      array(
-        'class' => 'auth-custom-message',
-      ),
-      $remarkup_view);
-  }
-
   private function newEmailLoginView(array $configs) {
     assert_instances_of($configs, 'PhabricatorAuthProviderConfig');
 

webroot/rsrc/css/application/auth/auth.css

@@ -57,7 +57,7 @@
 }
 
 .auth-custom-message {
-  margin: 32px auto 64px;
+  margin: 32px auto 48px;
   max-width: 548px;
   background: #fff;
   padding: 16px;