Issue #3248928: Redirect or provide link to apply form for user who started update if accessing start form

tests/src/Functional/UpdaterFormTest.php

@@ -239,6 +239,8 @@ class UpdaterFormTest extends AutomaticUpdatesFunctionalTestBase {
    * Tests deleting an existing update.
    */
   public function testDeleteExistingUpdate() {
+    $conflict_message = 'Cannot begin an update because another Composer operation is currently in progress.';
+
     $assert_session = $this->assertSession();
     $page = $this->getSession()->getPage();
     $this->setCoreVersion('9.8.0');
@@ -262,7 +264,7 @@ class UpdaterFormTest extends AutomaticUpdatesFunctionalTestBase {
     $page->pressButton('Cancel update');
     $assert_session->addressEquals('/admin/reports/updates/automatic-update');
     $assert_session->pageTextContains('The update was successfully cancelled.');
-    $assert_session->pageTextNotContains('Cannot begin an update because another Composer operation is currently in progress.');
+    $assert_session->pageTextNotContains($conflict_message);
     // Ensure we can start another update after deleting the existing one.
     $page->pressButton('Update');
     $this->checkForMetaRefresh();
@@ -277,8 +279,14 @@ class UpdaterFormTest extends AutomaticUpdatesFunctionalTestBase {
     $account = $this->createUser([], NULL, TRUE);
     $this->drupalLogin($account);
     $this->drupalGet('/admin/reports/updates/automatic-update');
-    $assert_session->pageTextContains('Cannot begin an update because another Composer operation is currently in progress.');
+    $assert_session->pageTextContains($conflict_message);
     $assert_session->buttonNotExists('Update');
+    // We should be able to delete the previous update, and then we should be
+    // able to start a new one.
+    $page->pressButton('Delete existing update');
+    $assert_session->pageTextContains('Staged update deleted');
+    $assert_session->pageTextNotContains($conflict_message);
+    $assert_session->buttonExists('Update');
   }
 
   /**