Make "Land Revision" show merge conflicts more clearly

Summary:
Ref T182. We just show "an error happened" right now. Improve this behavior.

This error handling chain is a bit ad-hoc for now but we can formalize it as we hit other cases.

Test Plan:
{F910247}

{F910248}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T182

Differential Revision: https://secure.phabricator.com/D14343

src/applications/drydock/blueprint/DrydockWorkingCopyBlueprintImplementation.php

@@ -3,6 +3,8 @@
 final class DrydockWorkingCopyBlueprintImplementation
   extends DrydockBlueprintImplementation {
 
+  const PHASE_SQUASHMERGE = 'squashmerge';
+
   public function isEnabled() {
     return true;
   }
@@ -288,7 +290,7 @@ final class DrydockWorkingCopyBlueprintImplementation
       $merges = idx($spec, 'merges');
       if ($merges) {
         foreach ($merges as $merge) {
-          $this->applyMerge($interface, $merge);
+          $this->applyMerge($lease, $interface, $merge);
         }
       }
 
@@ -416,6 +418,7 @@ final class DrydockWorkingCopyBlueprintImplementation
   }
 
   private function applyMerge(
+    DrydockLease $lease,
     DrydockCommandInterface $interface,
     array $merge) {
 
@@ -428,15 +431,48 @@ final class DrydockWorkingCopyBlueprintImplementation
       $src_ref,
       $src_ref);
 
+    $command = csprintf(
+      'git merge --no-stat --squash --ff-only -- %R',
+      $src_ref);
+
     try {
-      $interface->execx(
-        'git merge --no-stat --squash --ff-only -- %s',
-        $src_ref);
+      $interface->execx('%C', $command);
     } catch (CommandException $ex) {
-      // TODO: Specifically note this as a merge conflict.
+      $this->setWorkingCopyVCSErrorFromCommandException(
+        $lease,
+        self::PHASE_SQUASHMERGE,
+        $command,
+        $ex);
+
       throw $ex;
     }
   }
 
+  protected function setWorkingCopyVCSErrorFromCommandException(
+    DrydockLease $lease,
+    $phase,
+    $command,
+    CommandException $ex) {
+
+    $error = array(
+      'phase' => $phase,
+      'command' => (string)$command,
+      'raw' => (string)$ex->getCommand(),
+      'err' => $ex->getError(),
+      'stdout' => $ex->getStdout(),
+      'stderr' => $ex->getStderr(),
+    );
+
+    $lease->setAttribute('workingcopy.vcs.error', $error);
+  }
+
+  public function getWorkingCopyVCSError(DrydockLease $lease) {
+    $error = $lease->getAttribute('workingcopy.vcs.error');
+    if (!$error) {
+      return null;
+    } else {
+      return $error;
+    }
+  }
 
 }

src/applications/drydock/storage/DrydockRepositoryOperation.php

@@ -175,6 +175,14 @@ final class DrydockRepositoryOperation extends DrydockDAO
     return $this->getProperty('exec.leasePHID');
   }
 
+  public function setWorkingCopyVCSError(array $error) {
+    return $this->setProperty('exec.workingcopy.error', $error);
+  }
+
+  public function getWorkingCopyVCSError() {
+    return $this->getProperty('exec.workingcopy.error');
+  }
+
 
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */

src/applications/drydock/view/DrydockRepositoryOperationStatusView.php

@@ -73,12 +73,104 @@ final class DrydockRepositoryOperationStatusView
     if ($state != DrydockRepositoryOperation::STATE_FAIL) {
       $item->addAttribute($operation->getOperationCurrentStatus($viewer));
     } else {
-      // TODO: Make this more useful.
-      $item->addAttribute(pht('Operation encountered an error.'));
+      $vcs_error = $operation->getWorkingCopyVCSError();
+      if ($vcs_error) {
+        switch ($vcs_error['phase']) {
+          case DrydockWorkingCopyBlueprintImplementation::PHASE_SQUASHMERGE:
+            $message = pht(
+              'This change did not merge cleanly. This usually indicates '.
+              'that the change is out of date and needs to be updated.');
+            break;
+          default:
+            $message = pht(
+              'Operation encountered an error while performing repository '.
+              'operations.');
+            break;
+        }
+
+        $item->addAttribute($message);
+
+        $table = $this->renderVCSErrorTable($vcs_error);
+        list($links, $info) = $this->renderDetailToggles($table);
+
+        $item->addAttribute($links);
+        $item->appendChild($info);
+      } else {
+        $item->addAttribute(pht('Operation encountered an error.'));
+      }
     }
 
     return id(new PHUIObjectItemListView())
       ->addItem($item);
   }
 
+  private function renderVCSErrorTable(array $vcs_error) {
+    $rows = array();
+    $rows[] = array(pht('Command'), $vcs_error['command']);
+    $rows[] = array(pht('Error'), $vcs_error['err']);
+    $rows[] = array(pht('Stdout'), $vcs_error['stdout']);
+    $rows[] = array(pht('Stderr'), $vcs_error['stderr']);
+
+    $table = id(new AphrontTableView($rows))
+      ->setColumnClasses(
+        array(
+          'header',
+          'wide',
+        ));
+
+    return $table;
+  }
+
+  private function renderDetailToggles(AphrontTableView $table) {
+    $show_id = celerity_generate_unique_node_id();
+    $hide_id = celerity_generate_unique_node_id();
+    $info_id = celerity_generate_unique_node_id();
+
+    Javelin::initBehavior('phabricator-reveal-content');
+
+    $show_details = javelin_tag(
+      'a',
+      array(
+        'id' => $show_id,
+        'href' => '#',
+        'sigil' => 'reveal-content',
+        'mustcapture' => true,
+        'meta' => array(
+          'hideIDs' => array($show_id),
+          'showIDs' => array($hide_id, $info_id),
+        ),
+      ),
+      pht('Show Details'));
+
+    $hide_details = javelin_tag(
+      'a',
+      array(
+        'id' => $hide_id,
+        'href' => '#',
+        'sigil' => 'reveal-content',
+        'mustcapture' => true,
+        'style' => 'display: none',
+        'meta' => array(
+          'hideIDs' => array($hide_id, $info_id),
+          'showIDs' => array($show_id),
+        ),
+      ),
+      pht('Hide Details'));
+
+    $info = javelin_tag(
+      'div',
+      array(
+        'id' => $info_id,
+        'style' => 'display: none',
+      ),
+      $table);
+
+    $links = array(
+      $show_details,
+      $hide_details,
+    );
+
+    return array($links, $info);
+  }
+
 }

src/applications/drydock/worker/DrydockRepositoryOperationUpdateWorker.php

@@ -90,6 +90,9 @@ final class DrydockRepositoryOperationUpdateWorker
     // TODO: This is very similar to leasing in Harbormaster, maybe we can
     // share some of the logic?
 
+    $working_copy = new DrydockWorkingCopyBlueprintImplementation();
+    $working_copy_type = $working_copy->getType();
+
     $lease_phid = $operation->getProperty('exec.leasePHID');
     if ($lease_phid) {
       $lease = id(new DrydockLeaseQuery())
@@ -103,9 +106,6 @@ final class DrydockRepositoryOperationUpdateWorker
             $lease_phid));
       }
     } else {
-      $working_copy_type = id(new DrydockWorkingCopyBlueprintImplementation())
-        ->getType();
-
       $repository = $operation->getRepository();
 
       $allowed_phids = $repository->getAutomationBlueprintPHIDs();
@@ -138,6 +138,13 @@ final class DrydockRepositoryOperationUpdateWorker
     }
 
     if (!$lease->isActive()) {
+      $vcs_error = $working_copy->getWorkingCopyVCSError($lease);
+      if ($vcs_error) {
+        $operation
+          ->setWorkingCopyVCSError($vcs_error)
+          ->save();
+      }
+
       throw new PhabricatorWorkerPermanentFailureException(
         pht(
           'Lease "%s" never activated.',