diff --git a/includes/common.inc b/includes/common.inc
index 40a7919..8c144f4 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -990,7 +990,11 @@ function drupal_http_request($url, array $options = array()) {
   $response = preg_split("/\r\n|\n|\r/", $response);
 
   // Parse the response status line.
-  list($protocol, $code, $status_message) = explode(' ', trim(array_shift($response)), 3);
+  $response_status_array = _drupal_parse_response_status(trim(array_shift($response)));
+  $protocol = $response_status_array['http_version'];
+  $code = $response_status_array['response_code'];
+  $status_message = $response_status_array['reason_phrase'];
+
   $result->protocol = $protocol;
   $result->status_message = $status_message;
 
@@ -1090,6 +1094,38 @@ function drupal_http_request($url, array $options = array()) {
 }
 
 /**
+ * Split an HTTP response status line into components.
+ *
+ * Refactored out of drupal_http_request() so it can be unit tested.
+ *
+ * @link http://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html Status line definition @endlink
+ *
+ * @param string $respone
+ *   The response status line, e.g. 'HTTP/1.1 500 Internal Server Error'
+ *
+ * @return array
+ *   Keyed array containing the component parts. If the response is malformed,
+ *   all possible parts will be extracted. 'reason_phrase' could be empty.
+ *   Possible keys:
+ *   - 'http_version'
+ *   - 'response_code'
+ *   - 'reason_phrase'
+ */
+function _drupal_parse_response_status($response) {
+  $response_array = explode(' ', trim($response), 3);
+  // Set up empty values.
+  $result = array(
+    'reason_phrase' => '',
+  );
+  $result['http_version'] = $response_array[0];
+  $result['response_code'] = $response_array[1];
+  if (isset($response_array[2])) {
+    $result['reason_phrase'] = $response_array[2];
+  }
+  return $result;
+}
+
+/**
  * Helper function for determining hosts excluded from needing a proxy.
  *
  * @return
diff --git a/modules/simpletest/tests/common.test b/modules/simpletest/tests/common.test
index 44eecdc..936fdf5 100644
--- a/modules/simpletest/tests/common.test
+++ b/modules/simpletest/tests/common.test
@@ -1083,6 +1083,76 @@ class DrupalHTTPRequestTestCase extends DrupalWebTestCase {
 }
 
 /**
+ * Tests parsing of the HTTP response status line.
+ *
+ * @see _drupal_parse_response_status()
+ */
+class DrupalHTTPResponseStatusLineTest extends DrupalUnitTestCase {
+  public static function getInfo() {
+    return array(
+      'name' => '_drupal_parse_response_status()',
+      'description' => 'Perform unit tests on _drupal_parse_response_status()',
+      'group' => 'System',
+    );
+  }
+
+  /**
+   * Tests parsing HTTP response status line.
+   */
+  public function testStatusLine() {
+    // Grab the big array of test data from statusLineData().
+    $data = $this->statusLineData();
+    foreach($data as $test_case) {
+      $test_data = array_shift($test_case);
+      $expected = array_shift($test_case);
+
+      $outcome = _drupal_parse_response_status($test_data);
+
+      foreach(array_keys($expected) as $key) {
+        $this->assertIdentical($outcome[$key], $expected[$key]);
+      }
+    }
+  }
+
+  /**
+   * Data provider for testStatusLine().
+   *
+   * @return array
+   *   Test data.
+   */
+  protected function statusLineData() {
+    return array(
+      array(
+        'HTTP/1.1 200 OK',
+        array(
+          'http_version' => 'HTTP/1.1',
+          'response_code' => '200',
+          'reason_phrase' => 'OK',
+        ),
+      ),
+      // Data set with no reason phrase.
+      array(
+        'HTTP/1.1 200',
+        array(
+          'http_version' => 'HTTP/1.1',
+          'response_code' => '200',
+          'reason_phrase' => '',
+        ),
+      ),
+      // Arbitrary strings.
+      array(
+        'version code multi word explanation',
+        array(
+          'http_version' => 'version',
+          'response_code' => 'code',
+          'reason_phrase' => 'multi word explanation',
+        ),
+      ),
+    );
+  }
+}
+
+/**
  * Testing drupal_add_region_content and drupal_get_region_content.
  */
 class DrupalSetContentTestCase extends DrupalWebTestCase {