Issue #1616752 by Taran2L:Period in names of querystring items was being replaced with underscores.

link.module

@@ -578,20 +578,44 @@ function _link_parse_url($url) {
   // Separate out the query string, if any.
   if (strpos($url, '?') !== FALSE) {
     $query = substr($url, strpos($url, '?') + 1);
-    parse_str($query, $query_array);
-    // See http://drupal.org/node/1710578
-    foreach ($query_array as $key=> &$value) {
-      if ($value === '' && FALSE === strpos($query, $key . '=')) {
-        $value = NULL;
-      }
-    }
-    $url_parts['query'] = $query_array;
+    $url_parts['query'] = _link_parse_str($query);
     $url = substr($url, 0, strpos($url, '?'));
   }
   $url_parts['url'] = $url;
   return $url_parts;
 }
 
+/**
+ * Bacause parse_str replaces the following characters in query parameters name
+ * in order to maintain compability with deprecated register_globals directive:
+ *
+ *   - chr(32) ( ) (space)
+ *   - chr(46) (.) (dot)
+ *   - chr(91) ([) (open square bracket)
+ *   - chr(128) - chr(159) (various)
+ *
+ * @param string $query
+ *   Query to parse.
+ *
+ * @return Array
+ *   Array of query parameters.
+ *
+ * @see http://php.net/manual/en/language.variables.external.php#81080
+ */
+function _link_parse_str($query) {
+  $query_array = array();
+
+  $pairs = explode('&', $query);
+  foreach ($pairs as $pair) {
+    $name_value = explode('=', $pair);
+    $name = urldecode($name_value[0]);
+    $value = isset($name_value[1]) ? urldecode($name_value[1]) : NULL;
+    $query_array[$name] = $value;
+  }
+
+  return $query_array;
+}
+
 /**
  * Implements hook_theme().
  */

tests/link.crud_browser.test

@@ -116,6 +116,12 @@ class LinkUITest extends DrupalWebTestcase {
         'msg' => 'js url',
         'type' => self::LINK_INPUT_TYPE_BAD_URL
       ),
+      array(
+        'href' => 'http://ecs-es.kelkoo.es/ctl/go/sitesearchGo?.ts=1338833010331&.sig=qP9GXeEFH6syBzwmzYkxmsvp1EI-',
+        'label' => 'http://ecs-es.kelkoo.es/ctl/go/sitesearchGo?.ts=1338833010331&.sig=qP9GXeEFH6syBzwmzYkxmsvp1EI-',
+        'msg' => 'Url with . in querystring',
+        'type' => self::LINK_INPUT_TYPE_GOOD,
+      ),
     );
     $test_case = array(
       'href' => 'www.example.com/'. $this->randomName(),