Fixed problem in condition for rotation transformation that could lead to an access of an undefined array index (#44)

Author: naitsirch

src/Svg/Tag/AbstractTag.php

@@ -166,7 +166,8 @@ protected function applyTransform($attributes)
                         break;
 
                     case "rotate":
-                        if (isset($t[2]) || isset($t[3])) {
+                        if (isset($t[2])) {
+                            $t[3] = isset($t[3]) ? $t[3] : 0;
                             $surface->translate($t[2], $t[3]);
                             $surface->rotate($t[1]);
                             $surface->translate(-$t[2], -$t[3]);