Issue #808730 by awm, Anushka-mp, dpagini, Jo Fitzgerald, catch, johnv, venugopp, kim.pepper, kscheirer, miro_dietiker, Berdir, alexpott: Show the Revisions tab/page even when only one revision exists

core/modules/node/src/Access/NodeRevisionAccessCheck.php

@@ -119,22 +119,31 @@ class NodeRevisionAccessCheck implements AccessInterface {
         $this->access[$cid] = FALSE;
         return FALSE;
       }
-
+      // If the revisions checkbox is selected for the content type, display the
-      // There should be at least two revisions. If the vid of the given node
+      // revisions tab.
-      // and the vid of the default revision differ, then we already have two
+      $bundle_entity_type = $node->getEntityType()->getBundleEntityType();
-      // different revisions so there is no need for a separate database check.
+      $bundle_entity = \Drupal::entityTypeManager()->getStorage($bundle_entity_type)->load($bundle);
-      // Also, if you try to revert to or delete the default revision, that's
+      if ($bundle_entity->shouldCreateNewRevision() && $op === 'view') {
-      // not good.
-      if ($node->isDefaultRevision() && ($this->nodeStorage->countDefaultLanguageRevisions($node) == 1 || $op == 'update' || $op == 'delete')) {
-        $this->access[$cid] = FALSE;
-      }
-      elseif ($account->hasPermission('administer nodes')) {
         $this->access[$cid] = TRUE;
       }
       else {
-        // First check the access to the default revision and finally, if the
+        // There should be at least two revisions. If the vid of the given node
-        // node passed in is not the default revision then access to that, too.
+        // and the vid of the default revision differ, then we already have two
-        $this->access[$cid] = $this->nodeAccess->access($this->nodeStorage->load($node->id()), $op, $account) && ($node->isDefaultRevision() || $this->nodeAccess->access($node, $op, $account));
+        // different revisions so there is no need for a separate database
+        // check. Also, if you try to revert to or delete the default revision,
+        // that's not good.
+        if ($node->isDefaultRevision() && ($this->nodeStorage->countDefaultLanguageRevisions($node) == 1 || $op === 'update' || $op === 'delete')) {
+          $this->access[$cid] = FALSE;
+        }
+        elseif ($account->hasPermission('administer nodes')) {
+          $this->access[$cid] = TRUE;
+        }
+        else {
+          // First check the access to the default revision and finally, if the
+          // node passed in is not the default revision then check access to
+          // that, too.
+          $this->access[$cid] = $this->nodeAccess->access($this->nodeStorage->load($node->id()), $op, $account) && ($node->isDefaultRevision() || $this->nodeAccess->access($node, $op, $account));
+        }
       }
     }
 

core/modules/node/tests/src/Functional/NodeRevisionsTest.php

@@ -239,6 +239,17 @@ class NodeRevisionsTest extends NodeTestBase {
     $node->save();
 
     $this->drupalGet("node/" . $node->id() . "/revisions");
+    // Verify revisions is accessible since the type has revisions enabled.
+    $this->assertResponse(200);
+    // Check initial revision is shown on the node revisions overview page.
+    $this->assertText('Simple revision message (EN)');
+
+    // Verify that delete operation is inaccessible for the default revision.
+    $this->drupalGet("node/" . $node->id() . "/revisions/" . $node->getRevisionId() . "/delete");
+    $this->assertResponse(403);
+
+    // Verify that revert operation is inaccessible for the default revision.
+    $this->drupalGet("node/" . $node->id() . "/revisions/" . $node->getRevisionId() . "/revert");
     $this->assertResponse(403);
 
     // Create a new revision and new log message.
@@ -261,7 +272,10 @@ class NodeRevisionsTest extends NodeTestBase {
     $node->save();
 
     $this->drupalGet("node/" . $node->id() . "/revisions");
-    $this->assertResponse(403);
+    // Verify revisions is accessible since the type has revisions enabled.
+    $this->assertResponse(200);
+    // Check initial revision is shown on the node revisions overview page.
+    $this->assertText('Simple revision message (EN)');
 
     // Add a translation in 'DE' and create a new revision and new log message.
     $translation = $node->addTranslation('de');

core/modules/node/tests/src/Functional/NodeRevisionsUiBypassAccessTest.php

@@ -70,7 +70,8 @@ class NodeRevisionsUiBypassAccessTest extends NodeTestBase {
     $this->drupalPostForm('node/' . $node->id() . '/edit', $edit, 'Save');
 
     $this->assertUrl($node->toUrl());
-    $this->assertNoLink(t('Revisions'));
+    // Verify revisions exist since the content type has revisions enabled.
+    $this->assertLink(t('Revisions'));
 
     // Verify the checkbox is checked on the node edit form.
     $this->drupalGet('node/' . $node->id() . '/edit');
@@ -82,6 +83,40 @@ class NodeRevisionsUiBypassAccessTest extends NodeTestBase {
 
     $this->assertUrl($node->toUrl());
     $this->assertLink(t('Revisions'));
+
+    // Unset page revision setting 'create new revision'. This will mean new
+    // revisions are not created by default when the node is edited.
+    $type = NodeType::load('page');
+    $type->setNewRevision(FALSE);
+    $type->save();
+
+    // Create the node.
+    $node = $this->drupalCreateNode();
+
+    // Verify the checkbox is unchecked on the node edit form.
+    $this->drupalGet('node/' . $node->id() . '/edit');
+    $this->assertNoFieldChecked('edit-revision', "'Create new revision' checkbox is unchecked");
+    // Submit the form without changing the checkbox.
+    $edit = [];
+    $this->drupalPostForm('node/' . $node->id() . '/edit', $edit, 'Save');
+
+    $this->assertUrl($node->toUrl());
+    // Verify that no link to revisions is displayed since the type
+    // has the 'create new revision' setting unset.
+    $this->assertNoLink(t('Revisions'));
+
+    // Verify the checkbox is unchecked on the node edit form.
+    $this->drupalGet('node/' . $node->id() . '/edit');
+    $this->assertNoFieldChecked('edit-revision', "'Create new revision' checkbox is unchecked");
+
+    // Check the 'create new revision' checkbox and save the node.
+    $edit = ['revision' => TRUE];
+    $this->drupalPostForm('node/' . $node->id() . '/edit', $edit, 'Save');
+
+    $this->assertUrl($node->toUrl());
+    // Verify that the link is displayed since a new revision is created and
+    // the 'create new revision' checkbox on the node is checked.
+    $this->assertLink(t('Revisions'));
   }
 
 }