diff --git a/src/applications/audit/query/PhabricatorCommitSearchEngine.php b/src/applications/audit/query/PhabricatorCommitSearchEngine.php
index 0b7d01ad86..7f429dd596 100644
--- a/src/applications/audit/query/PhabricatorCommitSearchEngine.php
+++ b/src/applications/audit/query/PhabricatorCommitSearchEngine.php
@@ -1,203 +1,219 @@
 <?php
 
 final class PhabricatorCommitSearchEngine
   extends PhabricatorApplicationSearchEngine {
 
   public function getResultTypeDescription() {
     return pht('Commits');
   }
 
   public function getApplicationClassName() {
     return 'PhabricatorDiffusionApplication';
   }
 
   public function newQuery() {
     return id(new DiffusionCommitQuery())
       ->needAuditRequests(true)
       ->needCommitData(true)
       ->needDrafts(true);
   }
 
   protected function newResultBuckets() {
     return DiffusionCommitResultBucket::getAllResultBuckets();
   }
 
   protected function buildQueryFromParameters(array $map) {
     $query = $this->newQuery();
 
     if ($map['responsiblePHIDs']) {
       $query->withResponsiblePHIDs($map['responsiblePHIDs']);
     }
 
     if ($map['auditorPHIDs']) {
       $query->withAuditorPHIDs($map['auditorPHIDs']);
     }
 
     if ($map['authorPHIDs']) {
       $query->withAuthorPHIDs($map['authorPHIDs']);
     }
 
     if ($map['statuses']) {
       $query->withStatuses($map['statuses']);
     }
 
     if ($map['repositoryPHIDs']) {
       $query->withRepositoryPHIDs($map['repositoryPHIDs']);
     }
 
     if ($map['packagePHIDs']) {
       $query->withPackagePHIDs($map['packagePHIDs']);
     }
 
+    if ($map['unreachable'] !== null) {
+      $query->withUnreachable($map['unreachable']);
+    }
+
     return $query;
   }
 
   protected function buildCustomSearchFields() {
     return array(
       id(new PhabricatorSearchDatasourceField())
         ->setLabel(pht('Responsible Users'))
         ->setKey('responsiblePHIDs')
         ->setConduitKey('responsible')
         ->setAliases(array('responsible', 'responsibles', 'responsiblePHID'))
         ->setDatasource(new DifferentialResponsibleDatasource()),
       id(new PhabricatorUsersSearchField())
         ->setLabel(pht('Authors'))
         ->setKey('authorPHIDs')
         ->setConduitKey('authors')
         ->setAliases(array('author', 'authors', 'authorPHID')),
       id(new PhabricatorSearchDatasourceField())
         ->setLabel(pht('Auditors'))
         ->setKey('auditorPHIDs')
         ->setConduitKey('auditors')
         ->setAliases(array('auditor', 'auditors', 'auditorPHID'))
         ->setDatasource(new DiffusionAuditorFunctionDatasource()),
       id(new PhabricatorSearchCheckboxesField())
         ->setLabel(pht('Audit Status'))
         ->setKey('statuses')
         ->setAliases(array('status'))
         ->setOptions(PhabricatorAuditCommitStatusConstants::getStatusNameMap()),
       id(new PhabricatorSearchDatasourceField())
         ->setLabel(pht('Repositories'))
         ->setKey('repositoryPHIDs')
         ->setConduitKey('repositories')
         ->setAliases(array('repository', 'repositories', 'repositoryPHID'))
         ->setDatasource(new DiffusionRepositoryDatasource()),
       id(new PhabricatorSearchDatasourceField())
         ->setLabel(pht('Packages'))
         ->setKey('packagePHIDs')
         ->setConduitKey('packages')
         ->setAliases(array('package', 'packages', 'packagePHID'))
         ->setDatasource(new PhabricatorOwnersPackageDatasource()),
+      id(new PhabricatorSearchThreeStateField())
+        ->setLabel(pht('Unreachable'))
+        ->setKey('unreachable')
+        ->setOptions(
+          pht('(Show All)'),
+          pht('Show Only Unreachable Commits'),
+          pht('Hide Unreachable Commits'))
+        ->setDescription(
+          pht(
+            'Find or exclude unreachable commits which are not ancestors of '.
+            'any branch, tag, or ref.')),
     );
   }
 
   protected function getURI($path) {
     return '/diffusion/commit/'.$path;
   }
 
   protected function getBuiltinQueryNames() {
     $names = array();
 
     if ($this->requireViewer()->isLoggedIn()) {
       $names['active'] = pht('Active Audits');
       $names['authored'] = pht('Authored');
       $names['audited'] = pht('Audited');
     }
 
     $names['all'] = pht('All Commits');
 
     return $names;
   }
 
   public function buildSavedQueryFromBuiltin($query_key) {
     $query = $this->newSavedQuery();
     $query->setQueryKey($query_key);
     $viewer = $this->requireViewer();
 
     $viewer_phid = $viewer->getPHID();
     switch ($query_key) {
       case 'all':
         return $query;
       case 'active':
         $bucket_key = DiffusionCommitRequiredActionResultBucket::BUCKETKEY;
 
         $open = PhabricatorAuditCommitStatusConstants::getOpenStatusConstants();
 
         $query
           ->setParameter('responsiblePHIDs', array($viewer_phid))
           ->setParameter('statuses', $open)
-          ->setParameter('bucket', $bucket_key);
+          ->setParameter('bucket', $bucket_key)
+          ->setParameter('unreachable', false);
         return $query;
       case 'authored':
         $query
           ->setParameter('authorPHIDs', array($viewer_phid));
         return $query;
       case 'audited':
         $query
           ->setParameter('auditorPHIDs', array($viewer_phid));
         return $query;
     }
 
     return parent::buildSavedQueryFromBuiltin($query_key);
   }
 
   protected function renderResultList(
     array $commits,
     PhabricatorSavedQuery $query,
     array $handles) {
     assert_instances_of($commits, 'PhabricatorRepositoryCommit');
     $viewer = $this->requireViewer();
 
     $bucket = $this->getResultBucket($query);
 
     $template = id(new PhabricatorAuditListView())
       ->setViewer($viewer)
       ->setShowDrafts(true);
 
     $views = array();
     if ($bucket) {
       $bucket->setViewer($viewer);
 
       try {
         $groups = $bucket->newResultGroups($query, $commits);
 
         foreach ($groups as $group) {
           $views[] = id(clone $template)
             ->setHeader($group->getName())
             ->setNoDataString($group->getNoDataString())
             ->setCommits($group->getObjects());
         }
       } catch (Exception $ex) {
         $this->addError($ex->getMessage());
       }
     } else {
       $views[] = id(clone $template)
         ->setCommits($commits)
         ->setNoDataString(pht('No matching commits.'));
     }
 
     if (count($views) == 1) {
       $list = head($views)->buildList();
     } else {
       $list = $views;
     }
 
     $result = new PhabricatorApplicationSearchResultView();
     $result->setContent($list);
 
     return $result;
   }
 
   protected function getNewUserBody() {
 
     $view = id(new PHUIBigInfoView())
       ->setIcon('fa-check-circle-o')
       ->setTitle(pht('Welcome to Audit'))
       ->setDescription(
         pht('Post-commit code review and auditing. Audits you are assigned '.
             'to will appear here.'));
 
       return $view;
   }
 
 }
diff --git a/src/applications/audit/view/PhabricatorAuditListView.php b/src/applications/audit/view/PhabricatorAuditListView.php
index 9207230e7c..e249406724 100644
--- a/src/applications/audit/view/PhabricatorAuditListView.php
+++ b/src/applications/audit/view/PhabricatorAuditListView.php
@@ -1,181 +1,182 @@
 <?php
 
 final class PhabricatorAuditListView extends AphrontView {
 
   private $commits;
   private $header;
   private $showDrafts;
   private $noDataString;
   private $highlightedAudits;
 
   public function setNoDataString($no_data_string) {
     $this->noDataString = $no_data_string;
     return $this;
   }
 
   public function getNoDataString() {
     return $this->noDataString;
   }
 
   public function setHeader($header) {
     $this->header = $header;
     return $this;
   }
 
   public function getHeader() {
     return $this->header;
   }
 
   public function setShowDrafts($show_drafts) {
     $this->showDrafts = $show_drafts;
     return $this;
   }
 
   public function getShowDrafts() {
     return $this->showDrafts;
   }
 
   /**
    * These commits should have both commit data and audit requests attached.
    */
   public function setCommits(array $commits) {
     assert_instances_of($commits, 'PhabricatorRepositoryCommit');
     $this->commits = mpull($commits, null, 'getPHID');
     return $this;
   }
 
   public function getCommits() {
     return $this->commits;
   }
 
   private function getCommitDescription($phid) {
     if ($this->commits === null) {
       return pht('(Unknown Commit)');
     }
 
     $commit = idx($this->commits, $phid);
     if (!$commit) {
       return pht('(Unknown Commit)');
     }
 
     $summary = $commit->getCommitData()->getSummary();
     if (strlen($summary)) {
       return $summary;
     }
 
     // No summary, so either this is still impoting or just has an empty
     // commit message.
 
     if (!$commit->isImported()) {
       return pht('(Importing Commit...)');
     } else {
       return pht('(Untitled Commit)');
     }
   }
 
   public function render() {
     $list = $this->buildList();
     $list->setFlush(true);
     return $list->render();
   }
 
   public function buildList() {
     $viewer = $this->getViewer();
     $rowc = array();
 
     $phids = array();
     foreach ($this->getCommits() as $commit) {
       $phids[] = $commit->getPHID();
 
       foreach ($commit->getAudits() as $audit) {
         $phids[] = $audit->getAuditorPHID();
       }
 
       $author_phid = $commit->getAuthorPHID();
       if ($author_phid) {
         $phids[] = $author_phid;
       }
     }
 
     $handles = $viewer->loadHandles($phids);
 
     $show_drafts = $this->getShowDrafts();
 
     $draft_icon = id(new PHUIIconView())
       ->setIcon('fa-comment yellow')
       ->addSigil('has-tooltip')
       ->setMetadata(
         array(
           'tip' => pht('Unsubmitted Comments'),
         ));
 
     $list = new PHUIObjectItemListView();
     foreach ($this->commits as $commit) {
       $commit_phid = $commit->getPHID();
       $commit_handle = $handles[$commit_phid];
       $committed = null;
 
       $commit_name = $commit_handle->getName();
       $commit_link = $commit_handle->getURI();
       $commit_desc = $this->getCommitDescription($commit_phid);
       $committed = phabricator_datetime($commit->getEpoch(), $viewer);
 
       $status = $commit->getAuditStatus();
 
       $status_text =
         PhabricatorAuditCommitStatusConstants::getStatusName($status);
       $status_color =
         PhabricatorAuditCommitStatusConstants::getStatusColor($status);
       $status_icon =
         PhabricatorAuditCommitStatusConstants::getStatusIcon($status);
 
       $author_phid = $commit->getAuthorPHID();
       if ($author_phid) {
         $author_name = $handles[$author_phid]->renderLink();
       } else {
         $author_name = $commit->getCommitData()->getAuthorName();
       }
 
       $item = id(new PHUIObjectItemView())
         ->setObjectName($commit_name)
         ->setHeader($commit_desc)
         ->setHref($commit_link)
+        ->setDisabled($commit->isUnreachable())
         ->addByline(pht('Author: %s', $author_name))
         ->addIcon('none', $committed);
 
       if ($show_drafts) {
         if ($commit->getHasDraft($viewer)) {
           $item->addAttribute($draft_icon);
         }
       }
 
       $audits = $commit->getAudits();
       $auditor_phids = mpull($audits, 'getAuditorPHID');
       if ($auditor_phids) {
         $auditor_list = $handles->newSublist($auditor_phids)
           ->renderList()
           ->setAsInline(true);
       } else {
         $auditor_list = phutil_tag('em', array(), pht('None'));
       }
       $item->addAttribute(pht('Auditors: %s', $auditor_list));
 
       if ($status_color) {
         $item->setStatusIcon($status_icon.' '.$status_color, $status_text);
       }
 
       $list->addItem($item);
     }
 
     if ($this->noDataString) {
       $list->setNoDataString($this->noDataString);
     }
 
     if ($this->header) {
       $list->setHeader($this->header);
     }
 
     return $list;
   }
 
 }
diff --git a/src/applications/diffusion/query/DiffusionCommitQuery.php b/src/applications/diffusion/query/DiffusionCommitQuery.php
index 40fb5a64f6..1521f5770c 100644
--- a/src/applications/diffusion/query/DiffusionCommitQuery.php
+++ b/src/applications/diffusion/query/DiffusionCommitQuery.php
@@ -1,625 +1,646 @@
 <?php
 
 final class DiffusionCommitQuery
   extends PhabricatorCursorPagedPolicyAwareQuery {
 
   private $ids;
   private $phids;
   private $authorPHIDs;
   private $defaultRepository;
   private $identifiers;
   private $repositoryIDs;
   private $repositoryPHIDs;
   private $identifierMap;
   private $responsiblePHIDs;
   private $statuses;
   private $packagePHIDs;
+  private $unreachable;
 
   private $needAuditRequests;
   private $auditIDs;
   private $auditorPHIDs;
   private $epochMin;
   private $epochMax;
   private $importing;
 
   private $needCommitData;
   private $needDrafts;
 
   public function withIDs(array $ids) {
     $this->ids = $ids;
     return $this;
   }
 
   public function withPHIDs(array $phids) {
     $this->phids = $phids;
     return $this;
   }
 
   public function withAuthorPHIDs(array $phids) {
     $this->authorPHIDs = $phids;
     return $this;
   }
 
   /**
    * Load commits by partial or full identifiers, e.g. "rXab82393", "rX1234",
    * or "a9caf12". When an identifier matches multiple commits, they will all
    * be returned; callers should be prepared to deal with more results than
    * they queried for.
    */
   public function withIdentifiers(array $identifiers) {
     // Some workflows (like blame lookups) can pass in large numbers of
     // duplicate identifiers. We only care about unique identifiers, so
     // get rid of duplicates immediately.
     $identifiers = array_fuse($identifiers);
 
     $this->identifiers = $identifiers;
     return $this;
   }
 
   /**
    * Look up commits in a specific repository. This is a shorthand for calling
    * @{method:withDefaultRepository} and @{method:withRepositoryIDs}.
    */
   public function withRepository(PhabricatorRepository $repository) {
     $this->withDefaultRepository($repository);
     $this->withRepositoryIDs(array($repository->getID()));
     return $this;
   }
 
   /**
    * Look up commits in a specific repository. Prefer
    * @{method:withRepositoryIDs}; the underyling table is keyed by ID such
    * that this method requires a separate initial query to map PHID to ID.
    */
   public function withRepositoryPHIDs(array $phids) {
     $this->repositoryPHIDs = $phids;
     return $this;
   }
 
   /**
    * If a default repository is provided, ambiguous commit identifiers will
    * be assumed to belong to the default repository.
    *
    * For example, "r123" appearing in a commit message in repository X is
    * likely to be unambiguously "rX123". Normally the reference would be
    * considered ambiguous, but if you provide a default repository it will
    * be correctly resolved.
    */
   public function withDefaultRepository(PhabricatorRepository $repository) {
     $this->defaultRepository = $repository;
     return $this;
   }
 
   public function withRepositoryIDs(array $repository_ids) {
     $this->repositoryIDs = $repository_ids;
     return $this;
   }
 
   public function needCommitData($need) {
     $this->needCommitData = $need;
     return $this;
   }
 
   public function needDrafts($need) {
     $this->needDrafts = $need;
     return $this;
   }
 
   public function needAuditRequests($need) {
     $this->needAuditRequests = $need;
     return $this;
   }
 
   public function withAuditIDs(array $ids) {
     $this->auditIDs = $ids;
     return $this;
   }
 
   public function withAuditorPHIDs(array $auditor_phids) {
     $this->auditorPHIDs = $auditor_phids;
     return $this;
   }
 
   public function withResponsiblePHIDs(array $responsible_phids) {
     $this->responsiblePHIDs = $responsible_phids;
     return $this;
   }
 
   public function withPackagePHIDs(array $package_phids) {
     $this->packagePHIDs = $package_phids;
     return $this;
   }
 
+  public function withUnreachable($unreachable) {
+    $this->unreachable = $unreachable;
+    return $this;
+  }
+
   public function withStatuses(array $statuses) {
     $this->statuses = $statuses;
     return $this;
   }
 
   public function withEpochRange($min, $max) {
     $this->epochMin = $min;
     $this->epochMax = $max;
     return $this;
   }
 
   public function withImporting($importing) {
     $this->importing = $importing;
     return $this;
   }
 
   public function getIdentifierMap() {
     if ($this->identifierMap === null) {
       throw new Exception(
         pht(
           'You must %s the query before accessing the identifier map.',
           'execute()'));
     }
     return $this->identifierMap;
   }
 
   protected function getPrimaryTableAlias() {
     return 'commit';
   }
 
   protected function willExecute() {
     if ($this->identifierMap === null) {
       $this->identifierMap = array();
     }
   }
 
   public function newResultObject() {
     return new PhabricatorRepositoryCommit();
   }
 
   protected function loadPage() {
     return $this->loadStandardPage($this->newResultObject());
   }
 
   protected function willFilterPage(array $commits) {
     $repository_ids = mpull($commits, 'getRepositoryID', 'getRepositoryID');
     $repos = id(new PhabricatorRepositoryQuery())
       ->setViewer($this->getViewer())
       ->withIDs($repository_ids)
       ->execute();
 
     $min_qualified = PhabricatorRepository::MINIMUM_QUALIFIED_HASH;
     $result = array();
 
     foreach ($commits as $key => $commit) {
       $repo = idx($repos, $commit->getRepositoryID());
       if ($repo) {
         $commit->attachRepository($repo);
       } else {
         $this->didRejectResult($commit);
         unset($commits[$key]);
         continue;
       }
 
       // Build the identifierMap
       if ($this->identifiers !== null) {
         $ids = $this->identifiers;
         $prefixes = array(
           'r'.$commit->getRepository()->getCallsign(),
           'r'.$commit->getRepository()->getCallsign().':',
           'R'.$commit->getRepository()->getID().':',
           '', // No prefix is valid too and will only match the commitIdentifier
         );
         $suffix = $commit->getCommitIdentifier();
 
         if ($commit->getRepository()->isSVN()) {
           foreach ($prefixes as $prefix) {
             if (isset($ids[$prefix.$suffix])) {
               $result[$prefix.$suffix][] = $commit;
             }
           }
         } else {
           // This awkward construction is so we can link the commits up in O(N)
           // time instead of O(N^2).
           for ($ii = $min_qualified; $ii <= strlen($suffix); $ii++) {
             $part = substr($suffix, 0, $ii);
             foreach ($prefixes as $prefix) {
               if (isset($ids[$prefix.$part])) {
                 $result[$prefix.$part][] = $commit;
               }
             }
           }
         }
       }
     }
 
     if ($result) {
       foreach ($result as $identifier => $matching_commits) {
         if (count($matching_commits) == 1) {
           $result[$identifier] = head($matching_commits);
         } else {
           // This reference is ambiguous (it matches more than one commit) so
           // don't link it.
           unset($result[$identifier]);
         }
       }
       $this->identifierMap += $result;
     }
 
     return $commits;
   }
 
   protected function didFilterPage(array $commits) {
     $viewer = $this->getViewer();
 
     if ($this->needCommitData) {
       $data = id(new PhabricatorRepositoryCommitData())->loadAllWhere(
         'commitID in (%Ld)',
         mpull($commits, 'getID'));
       $data = mpull($data, null, 'getCommitID');
       foreach ($commits as $commit) {
         $commit_data = idx($data, $commit->getID());
         if (!$commit_data) {
           $commit_data = new PhabricatorRepositoryCommitData();
         }
         $commit->attachCommitData($commit_data);
       }
     }
 
     if ($this->needAuditRequests) {
       $requests = id(new PhabricatorRepositoryAuditRequest())->loadAllWhere(
         'commitPHID IN (%Ls)',
         mpull($commits, 'getPHID'));
 
       $requests = mgroup($requests, 'getCommitPHID');
       foreach ($commits as $commit) {
         $audit_requests = idx($requests, $commit->getPHID(), array());
         $commit->attachAudits($audit_requests);
         foreach ($audit_requests as $audit_request) {
           $audit_request->attachCommit($commit);
         }
       }
     }
 
     if ($this->needDrafts) {
       PhabricatorDraftEngine::attachDrafts(
         $viewer,
         $commits);
     }
 
     return $commits;
   }
 
   protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {
     $where = parent::buildWhereClauseParts($conn);
 
     if ($this->repositoryPHIDs !== null) {
       $map_repositories = id(new PhabricatorRepositoryQuery())
         ->setViewer($this->getViewer())
         ->withPHIDs($this->repositoryPHIDs)
         ->execute();
 
       if (!$map_repositories) {
         throw new PhabricatorEmptyQueryException();
       }
       $repository_ids = mpull($map_repositories, 'getID');
       if ($this->repositoryIDs !== null) {
         $repository_ids = array_merge($repository_ids, $this->repositoryIDs);
       }
       $this->withRepositoryIDs($repository_ids);
     }
 
     if ($this->ids !== null) {
       $where[] = qsprintf(
         $conn,
         'commit.id IN (%Ld)',
         $this->ids);
     }
 
     if ($this->phids !== null) {
       $where[] = qsprintf(
         $conn,
         'commit.phid IN (%Ls)',
         $this->phids);
     }
 
     if ($this->repositoryIDs !== null) {
       $where[] = qsprintf(
         $conn,
         'commit.repositoryID IN (%Ld)',
         $this->repositoryIDs);
     }
 
     if ($this->authorPHIDs !== null) {
       $where[] = qsprintf(
         $conn,
         'commit.authorPHID IN (%Ls)',
         $this->authorPHIDs);
     }
 
     if ($this->epochMin !== null) {
       $where[] = qsprintf(
         $conn,
         'commit.epoch >= %d',
         $this->epochMin);
     }
 
     if ($this->epochMax !== null) {
       $where[] = qsprintf(
         $conn,
         'commit.epoch <= %d',
         $this->epochMax);
     }
 
     if ($this->importing !== null) {
       if ($this->importing) {
         $where[] = qsprintf(
           $conn,
           '(commit.importStatus & %d) != %d',
           PhabricatorRepositoryCommit::IMPORTED_ALL,
           PhabricatorRepositoryCommit::IMPORTED_ALL);
       } else {
         $where[] = qsprintf(
           $conn,
           '(commit.importStatus & %d) = %d',
           PhabricatorRepositoryCommit::IMPORTED_ALL,
           PhabricatorRepositoryCommit::IMPORTED_ALL);
       }
     }
 
     if ($this->identifiers !== null) {
       $min_unqualified = PhabricatorRepository::MINIMUM_UNQUALIFIED_HASH;
       $min_qualified   = PhabricatorRepository::MINIMUM_QUALIFIED_HASH;
 
       $refs = array();
       $bare = array();
       foreach ($this->identifiers as $identifier) {
         $matches = null;
         preg_match('/^(?:[rR]([A-Z]+:?|[0-9]+:))?(.*)$/',
           $identifier, $matches);
         $repo = nonempty(rtrim($matches[1], ':'), null);
         $commit_identifier = nonempty($matches[2], null);
 
         if ($repo === null) {
           if ($this->defaultRepository) {
             $repo = $this->defaultRepository->getPHID();
           }
         }
 
         if ($repo === null) {
           if (strlen($commit_identifier) < $min_unqualified) {
             continue;
           }
           $bare[] = $commit_identifier;
         } else {
           $refs[] = array(
             'repository' => $repo,
             'identifier' => $commit_identifier,
           );
         }
       }
 
       $sql = array();
 
       foreach ($bare as $identifier) {
         $sql[] = qsprintf(
           $conn,
           '(commit.commitIdentifier LIKE %> AND '.
           'LENGTH(commit.commitIdentifier) = 40)',
           $identifier);
       }
 
       if ($refs) {
         $repositories = ipull($refs, 'repository');
 
         $repos = id(new PhabricatorRepositoryQuery())
           ->setViewer($this->getViewer())
           ->withIdentifiers($repositories);
         $repos->execute();
 
         $repos = $repos->getIdentifierMap();
         foreach ($refs as $key => $ref) {
           $repo = idx($repos, $ref['repository']);
           if (!$repo) {
             continue;
           }
 
           if ($repo->isSVN()) {
             if (!ctype_digit((string)$ref['identifier'])) {
               continue;
             }
             $sql[] = qsprintf(
               $conn,
               '(commit.repositoryID = %d AND commit.commitIdentifier = %s)',
               $repo->getID(),
               // NOTE: Because the 'commitIdentifier' column is a string, MySQL
               // ignores the index if we hand it an integer. Hand it a string.
               // See T3377.
               (int)$ref['identifier']);
           } else {
             if (strlen($ref['identifier']) < $min_qualified) {
               continue;
             }
 
             $identifier = $ref['identifier'];
             if (strlen($identifier) == 40) {
               // MySQL seems to do slightly better with this version if the
               // clause, so issue it if we have a full commit hash.
               $sql[] = qsprintf(
                 $conn,
                 '(commit.repositoryID = %d
                   AND commit.commitIdentifier = %s)',
                 $repo->getID(),
                 $identifier);
             } else {
               $sql[] = qsprintf(
                 $conn,
                 '(commit.repositoryID = %d
                   AND commit.commitIdentifier LIKE %>)',
                 $repo->getID(),
                 $identifier);
             }
           }
         }
       }
 
       if (!$sql) {
         // If we discarded all possible identifiers (e.g., they all referenced
         // bogus repositories or were all too short), make sure the query finds
         // nothing.
         throw new PhabricatorEmptyQueryException(
           pht('No commit identifiers.'));
       }
 
       $where[] = '('.implode(' OR ', $sql).')';
     }
 
     if ($this->auditIDs !== null) {
       $where[] = qsprintf(
         $conn,
         'auditor.id IN (%Ld)',
         $this->auditIDs);
     }
 
     if ($this->auditorPHIDs !== null) {
       $where[] = qsprintf(
         $conn,
         'auditor.auditorPHID IN (%Ls)',
         $this->auditorPHIDs);
     }
 
     if ($this->responsiblePHIDs !== null) {
       $where[] = qsprintf(
         $conn,
         '(audit.auditorPHID IN (%Ls) OR commit.authorPHID IN (%Ls))',
         $this->responsiblePHIDs,
         $this->responsiblePHIDs);
     }
 
     if ($this->statuses !== null) {
       $where[] = qsprintf(
         $conn,
         'commit.auditStatus IN (%Ls)',
         $this->statuses);
     }
 
     if ($this->packagePHIDs !== null) {
       $where[] = qsprintf(
         $conn,
         'package.dst IN (%Ls)',
         $this->packagePHIDs);
     }
 
+    if ($this->unreachable !== null) {
+      if ($this->unreachable) {
+        $where[] = qsprintf(
+          $conn,
+          '(commit.importStatus & %d) = %d',
+          PhabricatorRepositoryCommit::IMPORTED_UNREACHABLE,
+          PhabricatorRepositoryCommit::IMPORTED_UNREACHABLE);
+      } else {
+        $where[] = qsprintf(
+          $conn,
+          '(commit.importStatus & %d) = 0',
+          PhabricatorRepositoryCommit::IMPORTED_UNREACHABLE);
+      }
+    }
+
     return $where;
   }
 
   protected function didFilterResults(array $filtered) {
     if ($this->identifierMap) {
       foreach ($this->identifierMap as $name => $commit) {
         if (isset($filtered[$commit->getPHID()])) {
           unset($this->identifierMap[$name]);
         }
       }
     }
   }
 
   private function shouldJoinAuditor() {
     return ($this->auditIDs || $this->auditorPHIDs);
   }
 
   private function shouldJoinAudit() {
     return (bool)$this->responsiblePHIDs;
   }
 
   private function shouldJoinOwners() {
     return (bool)$this->packagePHIDs;
   }
 
   protected function buildJoinClauseParts(AphrontDatabaseConnection $conn) {
     $join = parent::buildJoinClauseParts($conn);
     $audit_request = new PhabricatorRepositoryAuditRequest();
 
     if ($this->shouldJoinAuditor()) {
       $join[] = qsprintf(
         $conn,
         'JOIN %T auditor ON commit.phid = auditor.commitPHID',
         $audit_request->getTableName());
     }
 
     if ($this->shouldJoinAudit()) {
       $join[] = qsprintf(
         $conn,
         'LEFT JOIN %T audit ON commit.phid = audit.commitPHID',
         $audit_request->getTableName());
     }
 
     if ($this->shouldJoinOwners()) {
       $join[] = qsprintf(
         $conn,
         'JOIN %T package ON commit.phid = package.src
           AND package.type = %s',
         PhabricatorEdgeConfig::TABLE_NAME_EDGE,
         DiffusionCommitHasPackageEdgeType::EDGECONST);
     }
 
     return $join;
   }
 
   protected function shouldGroupQueryResultRows() {
     if ($this->shouldJoinAuditor()) {
       return true;
     }
 
     if ($this->shouldJoinAudit()) {
       return true;
     }
 
     if ($this->shouldJoinOwners()) {
       return true;
     }
 
     return parent::shouldGroupQueryResultRows();
   }
 
   public function getQueryApplicationClass() {
     return 'PhabricatorDiffusionApplication';
   }
 
   public function getOrderableColumns() {
     return parent::getOrderableColumns() + array(
       'epoch' => array(
         'table' => $this->getPrimaryTableAlias(),
         'column' => 'epoch',
         'type' => 'int',
         'reverse' => false,
       ),
     );
   }
 
   protected function getPagingValueMap($cursor, array $keys) {
     $commit = $this->loadCursorObject($cursor);
     return array(
       'id' => $commit->getID(),
       'epoch' => $commit->getEpoch(),
     );
   }
 
   public function getBuiltinOrders() {
     $parent = parent::getBuiltinOrders();
 
     // Rename the default ID-based orders.
     $parent['importnew'] = array(
       'name' => pht('Import Date (Newest First)'),
     ) + $parent['newest'];
 
     $parent['importold'] = array(
       'name' => pht('Import Date (Oldest First)'),
     ) + $parent['oldest'];
 
     return array(
       'newest' => array(
         'vector' => array('epoch', 'id'),
         'name' => pht('Commit Date (Newest First)'),
       ),
       'oldest' => array(
         'vector' => array('-epoch', '-id'),
         'name' => pht('Commit Date (Oldest First)'),
       ),
     ) + $parent;
   }
 
 
 }
diff --git a/src/applications/diffusion/query/DiffusionCommitRequiredActionResultBucket.php b/src/applications/diffusion/query/DiffusionCommitRequiredActionResultBucket.php
index 405e1ecd27..41840bcb72 100644
--- a/src/applications/diffusion/query/DiffusionCommitRequiredActionResultBucket.php
+++ b/src/applications/diffusion/query/DiffusionCommitRequiredActionResultBucket.php
@@ -1,187 +1,191 @@
 <?php
 
 final class DiffusionCommitRequiredActionResultBucket
   extends DiffusionCommitResultBucket {
 
   const BUCKETKEY = 'action';
 
   private $objects;
 
   public function getResultBucketName() {
     return pht('Bucket by Required Action');
   }
 
   protected function buildResultGroups(
     PhabricatorSavedQuery $query,
     array $objects) {
 
     $this->objects = $objects;
 
     $phids = $query->getEvaluatedParameter('responsiblePHIDs', array());
     if (!$phids) {
       throw new Exception(
         pht(
           'You can not bucket results by required action without '.
           'specifying "Responsible Users".'));
     }
     $phids = array_fuse($phids);
 
     $groups = array();
 
     $groups[] = $this->newGroup()
       ->setName(pht('Needs Attention'))
       ->setNoDataString(pht('None of your commits have active concerns.'))
       ->setObjects($this->filterConcernRaised($phids));
 
     $groups[] = $this->newGroup()
       ->setName(pht('Needs Verification'))
       ->setNoDataString(pht('No commits are awaiting your verification.'))
       ->setObjects($this->filterNeedsVerification($phids));
 
     $groups[] = $this->newGroup()
       ->setName(pht('Ready to Audit'))
       ->setNoDataString(pht('No commits are waiting for you to audit them.'))
       ->setObjects($this->filterShouldAudit($phids));
 
     $groups[] = $this->newGroup()
       ->setName(pht('Waiting on Authors'))
       ->setNoDataString(pht('None of your audits are waiting on authors.'))
       ->setObjects($this->filterWaitingOnAuthors($phids));
 
     $groups[] = $this->newGroup()
       ->setName(pht('Waiting on Auditors'))
       ->setNoDataString(pht('None of your commits are waiting on audit.'))
       ->setObjects($this->filterWaitingOnAuditors($phids));
 
     // Because you can apply these buckets to queries which include revisions
     // that have been closed, add an "Other" bucket if we still have stuff
     // that didn't get filtered into any of the previous buckets.
     if ($this->objects) {
       $groups[] = $this->newGroup()
         ->setName(pht('Other Commits'))
         ->setObjects($this->objects);
     }
 
     return $groups;
   }
 
   private function filterConcernRaised(array $phids) {
     $results = array();
     $objects = $this->objects;
 
     $status_concern = PhabricatorAuditCommitStatusConstants::CONCERN_RAISED;
 
     foreach ($objects as $key => $object) {
       if (empty($phids[$object->getAuthorPHID()])) {
         continue;
       }
 
       if ($object->getAuditStatus() != $status_concern) {
         continue;
       }
 
       $results[$key] = $object;
       unset($this->objects[$key]);
     }
 
     return $results;
   }
 
   private function filterNeedsVerification(array $phids) {
     $results = array();
     $objects = $this->objects;
 
     $status_verify = PhabricatorAuditCommitStatusConstants::NEEDS_VERIFICATION;
     $has_concern = array(
       PhabricatorAuditStatusConstants::CONCERNED,
     );
     $has_concern = array_fuse($has_concern);
 
     foreach ($objects as $key => $object) {
       if (isset($phids[$object->getAuthorPHID()])) {
         continue;
       }
 
       if ($object->getAuditStatus() != $status_verify) {
         continue;
       }
 
       if (!$this->hasAuditorsWithStatus($object, $phids, $has_concern)) {
         continue;
       }
 
       $results[$key] = $object;
       unset($this->objects[$key]);
     }
 
     return $results;
   }
 
   private function filterShouldAudit(array $phids) {
     $results = array();
     $objects = $this->objects;
 
     $should_audit = array(
       PhabricatorAuditStatusConstants::AUDIT_REQUIRED,
       PhabricatorAuditStatusConstants::AUDIT_REQUESTED,
     );
     $should_audit = array_fuse($should_audit);
 
     foreach ($objects as $key => $object) {
+      if (isset($phids[$object->getAuthorPHID()])) {
+        continue;
+      }
+
       if (!$this->hasAuditorsWithStatus($object, $phids, $should_audit)) {
         continue;
       }
 
       $results[$key] = $object;
       unset($this->objects[$key]);
     }
 
     return $results;
   }
 
   private function filterWaitingOnAuthors(array $phids) {
     $results = array();
     $objects = $this->objects;
 
     $status_concern = PhabricatorAuditCommitStatusConstants::CONCERN_RAISED;
 
     foreach ($objects as $key => $object) {
       if ($object->getAuditStatus() != $status_concern) {
         continue;
       }
 
       if (isset($phids[$object->getAuthorPHID()])) {
         continue;
       }
 
       $results[$key] = $object;
       unset($this->objects[$key]);
     }
 
     return $results;
   }
 
   private function filterWaitingOnAuditors(array $phids) {
     $results = array();
     $objects = $this->objects;
 
     $status_waiting = array(
       PhabricatorAuditCommitStatusConstants::NEEDS_AUDIT,
       PhabricatorAuditCommitStatusConstants::NEEDS_VERIFICATION,
       PhabricatorAuditCommitStatusConstants::PARTIALLY_AUDITED,
     );
     $status_waiting = array_fuse($status_waiting);
 
     foreach ($objects as $key => $object) {
       if (empty($status_waiting[$object->getAuditStatus()])) {
         continue;
       }
 
       $results[$key] = $object;
       unset($this->objects[$key]);
     }
 
     return $results;
   }
 
 }