diff --git a/src/applications/diffusion/protocol/DiffusionSubversionWireProtocol.php b/src/applications/diffusion/protocol/DiffusionSubversionWireProtocol.php
index 1cb0f107aa..251967f314 100644
--- a/src/applications/diffusion/protocol/DiffusionSubversionWireProtocol.php
+++ b/src/applications/diffusion/protocol/DiffusionSubversionWireProtocol.php
@@ -33,7 +33,24 @@ final class DiffusionSubversionWireProtocol extends Phobject {
 
     $messages = array();
     while (true) {
-      if ($this->state == 'item') {
+      if ($this->state == 'space') {
+        // Consume zero or more extra spaces after matching an item. The
+        // protocol requires at least one space, but allows more than one.
+
+        $matches = null;
+        if (!preg_match('/^(\s*)\S/', $this->buffer, $matches)) {
+         // Wait for more data.
+          break;
+        }
+
+        // We have zero or more spaces and then some other character, so throw
+        // the spaces away and continue parsing frames.
+        if (strlen($matches[1])) {
+          $this->buffer = substr($this->buffer, strlen($matches[1]));
+        }
+
+        $this->state = 'item';
+      } else if ($this->state == 'item') {
         $match = null;
         $result = null;
         $buf = $this->buffer;
@@ -69,6 +86,12 @@ final class DiffusionSubversionWireProtocol extends Phobject {
             );
             $this->raw = '';
           }
+
+          // Consume any extra whitespace after an item. If we're in the
+          // "bytes" state, we aren't looking for whitespace.
+          if ($this->state == 'item') {
+            $this->state = 'space';
+          }
         } else {
           // No matches yet, wait for more data.
           break;
@@ -90,7 +113,7 @@ final class DiffusionSubversionWireProtocol extends Phobject {
           // Strip off the terminal space.
           $this->pushItem(substr($this->byteBuffer, 0, -1), 'string');
           $this->byteBuffer = '';
-          $this->state = 'item';
+          $this->state = 'space';
         }
       } else {
         throw new Exception(pht("Invalid state '%s'!", $this->state));
diff --git a/src/applications/diffusion/protocol/__tests__/DiffusionSubversionWireProtocolTestCase.php b/src/applications/diffusion/protocol/__tests__/DiffusionSubversionWireProtocolTestCase.php
index bd99b82035..f4309b0e7b 100644
--- a/src/applications/diffusion/protocol/__tests__/DiffusionSubversionWireProtocolTestCase.php
+++ b/src/applications/diffusion/protocol/__tests__/DiffusionSubversionWireProtocolTestCase.php
@@ -59,6 +59,50 @@ final class DiffusionSubversionWireProtocolTestCase
           ),
         ),
       ));
+
+    // This is testing that multiple spaces are parsed correctly. See T13140
+    // for discussion.
+    $this->assertSameSubversionMessages(
+      '( get-file true  false ) ',
+      //               ^-- Note extra space!
+      array(
+        array(
+          array(
+            'type' => 'word',
+            'value' => 'get-file',
+          ),
+          array(
+            'type' => 'word',
+            'value' => 'true',
+          ),
+          array(
+            'type' => 'word',
+            'value' => 'false',
+          ),
+        ),
+      ),
+      '( get-file true false ) ');
+
+    $this->assertSameSubversionMessages(
+      '( duck 5:quack    moo  ) ',
+      array(
+        array(
+          array(
+            'type' => 'word',
+            'value' => 'duck',
+          ),
+          array(
+            'type' => 'string',
+            'value' => 'quack',
+          ),
+          array(
+            'type' => 'word',
+            'value' => 'moo',
+          ),
+        ),
+      ),
+      '( duck 5:quack moo ) ');
+
   }
 
   public function testSubversionWireProtocolPartialFrame() {
@@ -86,7 +130,11 @@ final class DiffusionSubversionWireProtocolTestCase
       ipull($msg2, 'structure'));
   }
 
-  private function assertSameSubversionMessages($string, array $structs) {
+  private function assertSameSubversionMessages(
+    $string,
+    array $structs,
+    $serial_string = null) {
+
     $proto = new DiffusionSubversionWireProtocol();
 
     // Verify that the wire message parses into the structs.
@@ -100,6 +148,13 @@ final class DiffusionSubversionWireProtocolTestCase
       $serial[] = $proto->serializeStruct($struct);
     }
     $serial = implode('', $serial);
-    $this->assertEqual($string, $serial, 'serialize<'.$string.'>');
+
+    if ($serial_string === null) {
+      $expect_serial = $string;
+    } else {
+      $expect_serial = $serial_string;
+    }
+
+    $this->assertEqual($expect_serial, $serial, 'serialize<'.$string.'>');
   }
 }