[glyf] Don't translate/transform components if has no effect

src/hb-ot-var-gvar-table.hh

@@ -63,6 +63,9 @@ struct contour_point_vector_t : hb_vector_t<contour_point_t>
 
   void transform (const float (&matrix)[4])
   {
+    if (matrix[0] == 1.f && matrix[1] == 0.f &&
+	matrix[2] == 0.f && matrix[3] == 1.f)
+      return;
     for (unsigned int i = 0; i < length; i++)
     {
       contour_point_t &p = (*this)[i];
@@ -74,6 +77,8 @@ struct contour_point_vector_t : hb_vector_t<contour_point_t>
 
   void translate (const contour_point_t& delta)
   {
+    if (delta.x == 0.f && delta.y == 0.f)
+      return;
     for (unsigned int i = 0; i < length; i++)
       (*this)[i].translate (delta);
   }