From: René Dudfield <renesd@gmail.com>
Origin: https://github.com/pygame/pygame/pull/391
Subject: Fix arithmetic errors on some architextures
 [PATCH 1/3] Fix for 2d cross product of Vector2d with itself on ppc64le
 [PATCH 2/3] Skip blit self tests when using palette.
 [PATCH 3/3] Fix get_bounding_rect failure on ppc64.
--- a/src/math.c
+++ b/src/math.c
@@ -1969,6 +1969,8 @@ vector2_angle_to(PyVector *self, PyObjec
 {
     double angle;
     double other_coords[2];
+    if (self == other)
+        return PyFloat_FromDouble(0.0);
 
     if (!PyVectorCompatible_Check(other, self->dim)) {
         PyErr_SetString(PyExc_TypeError, "expected an vector.");