diff --git a/src/repository/api/ArcanistGitAPI.php b/src/repository/api/ArcanistGitAPI.php
--- a/src/repository/api/ArcanistGitAPI.php
+++ b/src/repository/api/ArcanistGitAPI.php
@@ -52,8 +52,12 @@
   }
 
   public function getGitVersion() {
-    list($stdout) = $this->execxLocal('--version');
-    return rtrim(str_replace('git version ', '', $stdout));
+    static $version = null;
+    if ($version === null) {
+      list($stdout) = $this->execxLocal('--version');
+      $version = rtrim(str_replace('git version ', '', $stdout));
+    }
+    return $version;
   }
 
   public function getMetadataPath() {
@@ -645,8 +649,70 @@
     return $this->executeSVNFindRev($hash, 'SVN');
   }
 
+  private function buildUncommittedStatusViaStatus() {
+    $status = $this->buildLocalFuture(
+      array(
+        'status --porcelain=2 -z',
+      ));
+    list($stdout) = $status->resolvex();
+
+    $result = new PhutilArrayWithDefaultValue();
+    $parts = explode("\0", $stdout);
+    while (count($parts) > 1) {
+      $entry = array_shift($parts);
+      $entry_parts = explode(' ', $entry);
+      if ($entry_parts[0] == '1') {
+        $path = $entry_parts[8];
+      } else if ($entry_parts[0] == '2') {
+        $path = $entry_parts[9];
+      } else if ($entry_parts[0] == 'u') {
+        $path = $entry_parts[10];
+      } else if ($entry_parts[0] == '?') {
+        $result[$entry_parts[1]] = self::FLAG_UNTRACKED;
+        continue;
+      }
+
+      $result[$path] |= self::FLAG_UNCOMMITTED;
+      $index_state = substr($entry_parts[1], 0, 1);
+      $working_state = substr($entry_parts[1], 1, 1);
+      if ($index_state == 'A') {
+        $result[$path] |= self::FLAG_ADDED;
+      } else if ($index_state == 'M') {
+        $result[$path] |= self::FLAG_MODIFIED;
+      } else if ($index_state == 'D') {
+        $result[$path] |= self::FLAG_DELETED;
+      }
+      if ($working_state != '.') {
+        $result[$path] |= self::FLAG_UNSTAGED;
+        if ($index_state == '.') {
+          if ($working_state == 'A') {
+            $result[$path] |= self::FLAG_ADDED;
+          } else if ($working_state == 'M') {
+            $result[$path] |= self::FLAG_MODIFIED;
+          } else if ($working_state == 'D') {
+            $result[$path] |= self::FLAG_DELETED;
+          }
+        }
+      }
+      $submodule_tracked = substr($entry_parts[2], 2, 1);
+      $submodule_untracked = substr($entry_parts[2], 3, 1);
+      if ($submodule_tracked == 'M' || $submodule_untracked == 'U') {
+        $result[$path] |= self::FLAG_EXTERNALS;
+      }
+
+      if ($entry_parts[0] == '2') {
+        $result[array_shift($parts)] = $result[$path] | self::FLAG_DELETED;
+        $result[$path] |= self::FLAG_ADDED;
+      }
+    }
+    return $result->toArray();
+  }
 
   protected function buildUncommittedStatus() {
+    if (version_compare($this->getGitVersion(), '2.11.0', '>=')) {
+      return $this->buildUncommittedStatusViaStatus();
+    }
+
     $diff_options = $this->getDiffBaseOptions();
 
     if ($this->repositoryHasNoCommits) {
@@ -719,7 +785,7 @@
 
   protected function buildCommitRangeStatus() {
     list($stdout, $stderr) = $this->execxLocal(
-      'diff %C --raw %s --',
+      'diff %C --raw %s HEAD --',
       $this->getDiffBaseOptions(),
       $this->getBaseCommit());
 
diff --git a/src/repository/api/ArcanistMercurialAPI.php b/src/repository/api/ArcanistMercurialAPI.php
--- a/src/repository/api/ArcanistMercurialAPI.php
+++ b/src/repository/api/ArcanistMercurialAPI.php
@@ -372,41 +372,18 @@
   }
 
   protected function buildCommitRangeStatus() {
-    // TODO: Possibly we should use "hg status --rev X --rev ." for this
-    // instead, but we must run "hg diff" later anyway in most cases, so
-    // building and caching it shouldn't hurt us.
+    list($stdout) = $this->execxLocal(
+      'status --rev %s --rev tip',
+      $this->getBaseCommit());
 
-    $diff = $this->getFullMercurialDiff();
-    if (!$diff) {
-      return array();
-    }
+    $results = new PhutilArrayWithDefaultValue();
 
-    $parser = new ArcanistDiffParser();
-    $changes = $parser->parseDiff($diff);
-
-    $status_map = array();
-    foreach ($changes as $change) {
-      $flags = 0;
-      switch ($change->getType()) {
-        case ArcanistDiffChangeType::TYPE_ADD:
-        case ArcanistDiffChangeType::TYPE_MOVE_HERE:
-        case ArcanistDiffChangeType::TYPE_COPY_HERE:
-          $flags |= self::FLAG_ADDED;
-          break;
-        case ArcanistDiffChangeType::TYPE_CHANGE:
-        case ArcanistDiffChangeType::TYPE_COPY_AWAY: // Check for changes?
-          $flags |= self::FLAG_MODIFIED;
-          break;
-        case ArcanistDiffChangeType::TYPE_DELETE:
-        case ArcanistDiffChangeType::TYPE_MOVE_AWAY:
-        case ArcanistDiffChangeType::TYPE_MULTICOPY:
-          $flags |= self::FLAG_DELETED;
-          break;
-      }
-      $status_map[$change->getCurrentPath()] = $flags;
+    $working_status = ArcanistMercurialParser::parseMercurialStatus($stdout);
+    foreach ($working_status as $path => $mask) {
+      $results[$path] |= $mask;
     }
 
-    return $status_map;
+    return $results->toArray();
   }
 
   protected function didReloadWorkingCopy() {
diff --git a/src/repository/api/ArcanistSubversionAPI.php b/src/repository/api/ArcanistSubversionAPI.php
--- a/src/repository/api/ArcanistSubversionAPI.php
+++ b/src/repository/api/ArcanistSubversionAPI.php
@@ -45,9 +45,9 @@
   }
 
   protected function buildCommitRangeStatus() {
-    // In SVN, the commit range is always "uncommitted changes", so these
-    // statuses are equivalent.
-    return $this->getUncommittedStatus();
+    // In SVN, there are never any previous commits in the range -- it is all in
+    // the uncommitted status.
+    return array();
   }
 
   protected function buildUncommittedStatus() {
diff --git a/src/repository/api/__tests__/ArcanistRepositoryAPIStateTestCase.php b/src/repository/api/__tests__/ArcanistRepositoryAPIStateTestCase.php
--- a/src/repository/api/__tests__/ArcanistRepositoryAPIStateTestCase.php
+++ b/src/repository/api/__tests__/ArcanistRepositoryAPIStateTestCase.php
@@ -56,6 +56,16 @@
   }
 
   private function assertCorrectState($test, ArcanistRepositoryAPI $api) {
+    if ($api instanceof ArcanistGitAPI) {
+      $version = $api->getGitVersion();
+      if (version_compare($version, '2.11.0', '<')) {
+        // Behavior differs slightly on older versions of git; rather than code
+        // both variants, skip the tests in the presence of such a git.
+        $this->assertSkipped(pht('Behavior differs slightly on git < 2.11.0'));
+        return;
+      }
+    }
+
     $f_mod = ArcanistRepositoryAPI::FLAG_MODIFIED;
     $f_add = ArcanistRepositoryAPI::FLAG_ADDED;
     $f_del = ArcanistRepositoryAPI::FLAG_DELETED;
@@ -70,7 +80,22 @@
 
     switch ($test) {
       case 'svn_basic.svn.tgz':
-        $expect = array(
+        $expect_uncommitted = array(
+          'ADDED'       => $f_add,
+          'COPIED_TO'   => $f_add,
+          'DELETED'     => $f_del,
+          'MODIFIED'    => $f_mod,
+          'MOVED'       => $f_del,
+          'MOVED_TO'    => $f_add,
+          'PROPCHANGE'  => $f_mod,
+          'UNTRACKED'   => $f_unt,
+        );
+        $this->assertEqual($expect_uncommitted, $api->getUncommittedStatus());
+
+        $expect_range = array();
+        $this->assertEqual($expect_range, $api->getCommitRangeStatus());
+
+        $expect_working = array(
           'ADDED'       => $f_add,
           'COPIED_TO'   => $f_add,
           'DELETED'     => $f_del,
@@ -80,8 +105,7 @@
           'PROPCHANGE'  => $f_mod,
           'UNTRACKED'   => $f_unt,
         );
-        $this->assertEqual($expect, $api->getUncommittedStatus());
-        $this->assertEqual($expect, $api->getCommitRangeStatus());
+        $this->assertEqual($expect_working, $api->getWorkingCopyStatus());
         break;
       case 'git_basic.git.tgz':
         $expect_uncommitted = array(
@@ -96,10 +120,19 @@
           'ADDED'       => $f_add,
           'DELETED'     => $f_del,
           'MODIFIED'    => $f_mod,
-          'UNCOMMITTED' => $f_add,
           'UNSTAGED'    => $f_add,
         );
         $this->assertEqual($expect_range, $api->getCommitRangeStatus());
+
+        $expect_working = array(
+          'ADDED'       => $f_add,
+          'DELETED'     => $f_del,
+          'MODIFIED'    => $f_mod,
+          'UNCOMMITTED' => $f_add | $f_unc,
+          'UNSTAGED'    => $f_add | $f_mod | $f_uns | $f_unc,
+          'UNTRACKED'   => $f_unt,
+        );
+        $this->assertEqual($expect_working, $api->getWorkingCopyStatus());
         break;
       case 'git_submodules_dirty.git.tgz':
         $expect_uncommitted = array(
@@ -107,19 +140,19 @@
           'added/'                => $f_unt,
           'deleted'               => $f_del | $f_uns | $f_unc,
           'modified-commit'       => $f_mod | $f_uns | $f_unc,
-          'modified-commit-dirty' => $f_mod | $f_uns | $f_unc,
-          'modified-dirty'        => $f_ext | $f_uns | $f_unc,
+          'modified-commit-dirty' => $f_ext | $f_mod | $f_uns | $f_unc,
+          'modified-dirty'        => $f_ext | $f_mod | $f_uns | $f_unc,
         );
         $this->assertEqual($expect_uncommitted, $api->getUncommittedStatus());
         break;
       case 'git_submodules_staged.git.tgz':
         $expect_uncommitted = array(
-          '.gitmodules'           => $f_mod | $f_uns | $f_unc,
+          '.gitmodules'           => $f_mod | $f_unc,
           'added'                 => $f_add | $f_unc,
           'deleted'               => $f_del | $f_unc,
           'modified-commit'       => $f_mod | $f_unc,
-          'modified-commit-dirty' => $f_mod | $f_uns | $f_unc,
-          'modified-dirty'        => $f_ext | $f_uns | $f_unc,
+          'modified-commit-dirty' => $f_ext | $f_mod | $f_uns | $f_unc,
+          'modified-dirty'        => $f_ext | $f_mod | $f_uns | $f_unc,
         );
         $this->assertEqual($expect_uncommitted, $api->getUncommittedStatus());
         break;
@@ -137,6 +170,15 @@
           'UNCOMMITTED' => $f_add,
         );
         $this->assertEqual($expect_range, $api->getCommitRangeStatus());
+
+        $expect_working = array(
+          'ADDED'       => $f_add,
+          'DELETED'     => $f_del,
+          'MODIFIED'    => $f_mod,
+          'UNCOMMITTED' => $f_add | $f_mod | $f_unc,
+          'UNTRACKED'   => $f_unt,
+        );
+        $this->assertEqual($expect_working, $api->getWorkingCopyStatus());
         break;
       default:
         throw new Exception(