diff --git a/src/applications/differential/controller/DifferentialRevisionOperationController.php b/src/applications/differential/controller/DifferentialRevisionOperationController.php
index 85f2a0b1b2..a5d5b5f98f 100644
--- a/src/applications/differential/controller/DifferentialRevisionOperationController.php
+++ b/src/applications/differential/controller/DifferentialRevisionOperationController.php
@@ -1,153 +1,67 @@
 <?php
 
 final class DifferentialRevisionOperationController
   extends DifferentialController {
 
   public function handleRequest(AphrontRequest $request) {
     $viewer = $this->getViewer();
     $id = $request->getURIData('id');
 
     $revision = id(new DifferentialRevisionQuery())
       ->withIDs(array($id))
       ->setViewer($viewer)
       ->needActiveDiffs(true)
       ->executeOne();
     if (!$revision) {
       return new Aphront404Response();
     }
 
     $detail_uri = "/D{$id}";
 
-    $repository = $revision->getRepository();
-    if (!$repository) {
-      return $this->rejectOperation(
-        $revision,
-        pht('No Repository'),
-        pht(
-          'This revision is not associated with a known repository. Only '.
-          'revisions associated with a tracked repository can be landed '.
-          'automatically.'));
-    }
-
-    if (!$repository->canPerformAutomation()) {
-      return $this->rejectOperation(
-        $revision,
-        pht('No Repository Automation'),
-        pht(
-          'The repository this revision is associated with ("%s") is not '.
-          'configured to support automation. Configure automation for the '.
-          'repository to enable revisions to be landed automatically.',
-          $repository->getMonogram()));
-    }
-
-    // TODO: At some point we should allow installs to give "land reviewed
-    // code" permission to more users than "push any commit", because it is
-    // a much less powerful operation. For now, just require push so this
-    // doesn't do anything users can't do on their own.
-    $can_push = PhabricatorPolicyFilter::hasCapability(
-      $viewer,
-      $repository,
-      DiffusionPushCapability::CAPABILITY);
-    if (!$can_push) {
-      return $this->rejectOperation(
-        $revision,
-        pht('Unable to Push'),
-        pht(
-          'You do not have permission to push to the repository this '.
-          'revision is associated with ("%s"), so you can not land it.',
-          $repository->getMonogram()));
-    }
-
     $op = new DrydockLandRepositoryOperation();
-
-    // Check for other operations. Eventually this should probably be more
-    // general (e.g., it's OK to land to multiple different branches
-    // simultaneously) but just put this in as a sanity check for now.
-    $other_operations = id(new DrydockRepositoryOperationQuery())
-      ->setViewer($viewer)
-      ->withObjectPHIDs(array($revision->getPHID()))
-      ->withOperationTypes(
-        array(
-          $op->getOperationConstant(),
-        ))
-      ->withOperationStates(
-        array(
-          DrydockRepositoryOperation::STATE_WAIT,
-          DrydockRepositoryOperation::STATE_WORK,
-          DrydockRepositoryOperation::STATE_DONE,
-        ))
-      ->execute();
-
-    if ($other_operations) {
-      $any_done = false;
-      foreach ($other_operations as $operation) {
-        if ($operation->isDone()) {
-          $any_done = true;
-          break;
-        }
-      }
-
-      if ($any_done) {
-        return $this->rejectOperation(
-          $revision,
-          pht('Already Complete'),
-          pht('This revision has already landed.'));
-      } else {
-        return $this->rejectOperation(
-          $revision,
-          pht('Already In Flight'),
-          pht('This revision is already landing.'));
-      }
+    $barrier = $op->getBarrierToLanding($viewer, $revision);
+    if ($barrier) {
+      return $this->newDialog()
+        ->setTitle($barrier['title'])
+        ->appendParagraph($barrier['body'])
+        ->addCancelButton($detail_uri);
     }
 
     if ($request->isFormPost()) {
       // NOTE: The operation is locked to the current active diff, so if the
       // revision is updated before the operation applies nothing sneaky
       // occurs.
 
       $diff = $revision->getActiveDiff();
+      $repository = $revision->getRepository();
 
       $operation = DrydockRepositoryOperation::initializeNewOperation($op)
         ->setAuthorPHID($viewer->getPHID())
         ->setObjectPHID($revision->getPHID())
         ->setRepositoryPHID($repository->getPHID())
         ->setRepositoryTarget('branch:master')
         ->setProperty('differential.diffPHID', $diff->getPHID());
 
       $operation->save();
       $operation->scheduleUpdate();
 
       return id(new AphrontRedirectResponse())
         ->setURI($detail_uri);
     }
 
     return $this->newDialog()
       ->setTitle(pht('Land Revision'))
       ->appendParagraph(
         pht(
           'In theory, this will do approximately what `arc land` would do. '.
           'In practice, that is almost certainly not what it will actually '.
           'do.'))
       ->appendParagraph(
         pht(
           'THIS FEATURE IS EXPERIMENTAL AND DANGEROUS! USE IT AT YOUR '.
           'OWN RISK!'))
       ->addCancelButton($detail_uri)
       ->addSubmitButton(pht('Mutate Repository Unpredictably'));
   }
 
-  private function rejectOperation(
-    DifferentialRevision $revision,
-    $title,
-    $body) {
-
-    $id = $revision->getID();
-    $detail_uri = "/D{$id}";
-
-    return $this->newDialog()
-      ->setTitle($title)
-      ->appendParagraph($body)
-      ->addCancelButton($detail_uri);
-  }
-
 }
diff --git a/src/applications/differential/landing/DifferentialLandingActionMenuEventListener.php b/src/applications/differential/landing/DifferentialLandingActionMenuEventListener.php
index 7dcf3f462d..2cf3eaa4e5 100644
--- a/src/applications/differential/landing/DifferentialLandingActionMenuEventListener.php
+++ b/src/applications/differential/landing/DifferentialLandingActionMenuEventListener.php
@@ -1,69 +1,81 @@
 <?php
 
 /**
  * This class adds a "Land this" button to revision view.
  */
 final class DifferentialLandingActionMenuEventListener
   extends PhabricatorEventListener {
 
   public function register() {
     $this->listen(PhabricatorEventType::TYPE_UI_DIDRENDERACTIONS);
   }
 
   public function handleEvent(PhutilEvent $event) {
     switch ($event->getType()) {
       case PhabricatorEventType::TYPE_UI_DIDRENDERACTIONS:
         $this->handleActionsEvent($event);
       break;
     }
   }
 
   private function handleActionsEvent(PhutilEvent $event) {
     $object = $event->getValue('object');
     if ($object instanceof DifferentialRevision) {
       $this->renderRevisionAction($event);
     }
   }
 
   private function renderRevisionAction(PhutilEvent $event) {
-    if (!$this->canUseApplication($event->getUser())) {
+    $viewer = $event->getUser();
+
+    if (!$this->canUseApplication($viewer)) {
       return null;
     }
 
     $revision = $event->getValue('object');
 
     $repository = $revision->getRepository();
     if ($repository === null) {
       return null;
     }
 
     if ($repository->canPerformAutomation()) {
       $revision_id = $revision->getID();
 
+      $op = new DrydockLandRepositoryOperation();
+      $barrier = $op->getBarrierToLanding($viewer, $revision);
+
+      if ($barrier) {
+        $can_land = false;
+      } else {
+        $can_land = true;
+      }
+
       $action = id(new PhabricatorActionView())
-        ->setWorkflow(true)
         ->setName(pht('Land Revision'))
         ->setIcon('fa-fighter-jet')
-        ->setHref("/differential/revision/operation/{$revision_id}/");
+        ->setHref("/differential/revision/operation/{$revision_id}/")
+        ->setWorkflow(true)
+        ->setDisabled(!$can_land);
+
 
       $this->addActionMenuItems($event, $action);
     }
 
     $strategies = id(new PhutilClassMapQuery())
       ->setAncestorClass('DifferentialLandingStrategy')
       ->execute();
 
     foreach ($strategies as $strategy) {
-      $viewer = $event->getUser();
       $action = $strategy->createMenuItem($viewer, $revision, $repository);
       if ($action == null) {
         continue;
       }
       if ($strategy->isActionDisabled($viewer, $revision, $repository)) {
         $action->setDisabled(true);
       }
       $this->addActionMenuItems($event, $action);
     }
   }
 
 }
diff --git a/src/applications/drydock/operation/DrydockLandRepositoryOperation.php b/src/applications/drydock/operation/DrydockLandRepositoryOperation.php
index 00b5c71181..6da4c2ae5d 100644
--- a/src/applications/drydock/operation/DrydockLandRepositoryOperation.php
+++ b/src/applications/drydock/operation/DrydockLandRepositoryOperation.php
@@ -1,192 +1,289 @@
 <?php
 
 final class DrydockLandRepositoryOperation
   extends DrydockRepositoryOperationType {
 
   const OPCONST = 'land';
 
   public function getOperationDescription(
     DrydockRepositoryOperation $operation,
     PhabricatorUser $viewer) {
     return pht('Land Revision');
   }
 
   public function getOperationCurrentStatus(
     DrydockRepositoryOperation $operation,
     PhabricatorUser $viewer) {
 
     $target = $operation->getRepositoryTarget();
     $repository = $operation->getRepository();
     switch ($operation->getOperationState()) {
       case DrydockRepositoryOperation::STATE_WAIT:
         return pht(
           'Waiting to land revision into %s on %s...',
           $repository->getMonogram(),
           $target);
       case DrydockRepositoryOperation::STATE_WORK:
         return pht(
           'Landing revision into %s on %s...',
           $repository->getMonogram(),
           $target);
       case DrydockRepositoryOperation::STATE_DONE:
         return pht(
           'Revision landed into %s.',
           $repository->getMonogram());
     }
   }
 
   public function getWorkingCopyMerges(DrydockRepositoryOperation $operation) {
     $repository = $operation->getRepository();
     $merges = array();
 
     $object = $operation->getObject();
     if ($object instanceof DifferentialRevision) {
       $diff = $this->loadDiff($operation);
       $merges[] = array(
         'src.uri' => $repository->getStagingURI(),
         'src.ref' => $diff->getStagingRef(),
       );
     } else {
       throw new Exception(
         pht(
           'Invalid or unknown object ("%s") for land operation, expected '.
           'Differential Revision.',
           $operation->getObjectPHID()));
     }
 
     return $merges;
   }
 
   public function applyOperation(
     DrydockRepositoryOperation $operation,
     DrydockInterface $interface) {
     $viewer = $this->getViewer();
     $repository = $operation->getRepository();
 
     $cmd = array();
     $arg = array();
 
     $object = $operation->getObject();
     if ($object instanceof DifferentialRevision) {
       $revision = $object;
 
       $diff = $this->loadDiff($operation);
 
       $dict = $diff->getDiffAuthorshipDict();
       $author_name = idx($dict, 'authorName');
       $author_email = idx($dict, 'authorEmail');
 
       $api_method = 'differential.getcommitmessage';
       $api_params = array(
         'revision_id' => $revision->getID(),
       );
 
       $commit_message = id(new ConduitCall($api_method, $api_params))
         ->setUser($viewer)
         ->execute();
     } else {
       throw new Exception(
         pht(
           'Invalid or unknown object ("%s") for land operation, expected '.
           'Differential Revision.',
           $operation->getObjectPHID()));
     }
 
     $target = $operation->getRepositoryTarget();
     list($type, $name) = explode(':', $target, 2);
     switch ($type) {
       case 'branch':
         $push_dst = 'refs/heads/'.$name;
         break;
       default:
         throw new Exception(
           pht(
             'Unknown repository operation target type "%s" (in target "%s").',
             $type,
             $target));
     }
 
     $committer_info = $this->getCommitterInfo($operation);
 
     // NOTE: We're doing this commit with "-F -" so we don't run into trouble
     // with enormous commit messages which might otherwise exceed the maximum
     // size of a command.
 
     $future = $interface->getExecFuture(
       'git -c user.name=%s -c user.email=%s commit --author %s -F - --',
       $committer_info['name'],
       $committer_info['email'],
       "{$author_name} <{$author_email}>");
 
     $future
       ->write($commit_message)
       ->resolvex();
 
     $interface->execx(
       'git push origin -- %s:%s',
       'HEAD',
       $push_dst);
   }
 
   private function getCommitterInfo(DrydockRepositoryOperation $operation) {
     $viewer = $this->getViewer();
 
     $committer_name = null;
 
     $author_phid = $operation->getAuthorPHID();
     $object = id(new PhabricatorObjectQuery())
       ->setViewer($viewer)
       ->withPHIDs(array($author_phid))
       ->executeOne();
 
     if ($object) {
       if ($object instanceof PhabricatorUser) {
         $committer_name = $object->getUsername();
       }
     }
 
     if (!strlen($committer_name)) {
       $committer_name = pht('autocommitter');
     }
 
     // TODO: Probably let users choose a VCS email address in settings. For
     // now just make something up so we don't leak anyone's stuff.
 
     return array(
       'name' => $committer_name,
       'email' => 'autocommitter@example.com',
     );
   }
 
   private function loadDiff(DrydockRepositoryOperation $operation) {
     $viewer = $this->getViewer();
     $revision = $operation->getObject();
 
     $diff_phid = $operation->getProperty('differential.diffPHID');
 
     $diff = id(new DifferentialDiffQuery())
       ->setViewer($viewer)
       ->withPHIDs(array($diff_phid))
       ->executeOne();
     if (!$diff) {
       throw new Exception(
         pht(
           'Unable to load diff "%s".',
           $diff_phid));
     }
 
     $diff_revid = $diff->getRevisionID();
     $revision_id = $revision->getID();
     if ($diff_revid != $revision_id) {
       throw new Exception(
         pht(
           'Diff ("%s") has wrong revision ID ("%s", expected "%s").',
           $diff_phid,
           $diff_revid,
           $revision_id));
     }
 
     return $diff;
   }
 
+  public function getBarrierToLanding(
+    PhabricatorUser $viewer,
+    DifferentialRevision $revision) {
+
+    $repository = $revision->getRepository();
+    if (!$repository) {
+      return array(
+        'title' => pht('No Repository'),
+        'body' => pht(
+          'This revision is not associated with a known repository. Only '.
+          'revisions associated with a tracked repository can be landed '.
+          'automatically.'),
+      );
+    }
+
+    if (!$repository->canPerformAutomation()) {
+      return array(
+        'title' => pht('No Repository Automation'),
+        'body' => pht(
+          'The repository this revision is associated with ("%s") is not '.
+          'configured to support automation. Configure automation for the '.
+          'repository to enable revisions to be landed automatically.',
+          $repository->getMonogram()),
+      );
+    }
+
+    // TODO: At some point we should allow installs to give "land reviewed
+    // code" permission to more users than "push any commit", because it is
+    // a much less powerful operation. For now, just require push so this
+    // doesn't do anything users can't do on their own.
+    $can_push = PhabricatorPolicyFilter::hasCapability(
+      $viewer,
+      $repository,
+      DiffusionPushCapability::CAPABILITY);
+    if (!$can_push) {
+      return array(
+        'title' => pht('Unable to Push'),
+        'body' => pht(
+          'You do not have permission to push to the repository this '.
+          'revision is associated with ("%s"), so you can not land it.',
+          $repository->getMonogram()),
+      );
+    }
+
+    $status_accepted = ArcanistDifferentialRevisionStatus::ACCEPTED;
+    if ($revision->getStatus() !== $status_accepted) {
+      return array(
+        'title' => pht('Revision Not Accepted'),
+        'body' => pht(
+          'This revision is still under review. Only revisions which have '.
+          'been accepted may land.'),
+      );
+    }
+
+    // Check for other operations. Eventually this should probably be more
+    // general (e.g., it's OK to land to multiple different branches
+    // simultaneously) but just put this in as a sanity check for now.
+    $other_operations = id(new DrydockRepositoryOperationQuery())
+      ->setViewer($viewer)
+      ->withObjectPHIDs(array($revision->getPHID()))
+      ->withOperationTypes(
+        array(
+          $this->getOperationConstant(),
+        ))
+      ->withOperationStates(
+        array(
+          DrydockRepositoryOperation::STATE_WAIT,
+          DrydockRepositoryOperation::STATE_WORK,
+          DrydockRepositoryOperation::STATE_DONE,
+        ))
+      ->execute();
+
+    if ($other_operations) {
+      $any_done = false;
+      foreach ($other_operations as $operation) {
+        if ($operation->isDone()) {
+          $any_done = true;
+          break;
+        }
+      }
+
+      if ($any_done) {
+        return array(
+          'title' => pht('Already Complete'),
+          'body' => pht('This revision has already landed.'),
+        );
+      } else {
+        return array(
+          'title' => pht('Already In Flight'),
+          'body' => pht('This revision is already landing.'),
+        );
+      }
+    }
+
+    return null;
+  }
+
 }