From e9924ba6e4cb06f784e90c00eae0cc9c859d8190 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miguel=20S=C3=A1nchez=20de=20Le=C3=B3n=20Peque?=
 <peque@neosit.es>
Date: Thu, 12 Dec 2019 19:38:58 +0100
Subject: [PATCH] Fix plane rotation method

The vector defining the rotation is expected to be in local coordinates
and therefore needs to be converted to world coordinates before applying
the rotation.
---
 cadquery/occ_impl/geom.py |  2 +-
 tests/test_cadquery.py    | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/cadquery/occ_impl/geom.py b/cadquery/occ_impl/geom.py
index 0c31fe22..d959702a 100644
--- a/cadquery/occ_impl/geom.py
+++ b/cadquery/occ_impl/geom.py
@@ -619,7 +619,7 @@ class Plane(object):
         :param rotate: Vector [xDegrees, yDegrees, zDegrees]
         :return: a copy of this plane rotated as requested.
         """
-        rotate = Vector(rotate)
+        rotate = Vector(self.toWorldCoords(rotate))
         # Convert to radians.
         rotate = rotate.multiply(math.pi / 180.0)
 
diff --git a/tests/test_cadquery.py b/tests/test_cadquery.py
index ddd7cc45..64b85237 100644
--- a/tests/test_cadquery.py
+++ b/tests/test_cadquery.py
@@ -4,6 +4,9 @@
 """
 # system modules
 import math,os.path,time,tempfile
+from random import choice
+from random import random
+from random import randrange
 
 # my modules
 from cadquery import *
@@ -246,6 +249,32 @@ class TestCadQuery(BaseTest):
         self.assertEqual(-0.5, endPoint[1])
         self.assertEqual(2.5, endPoint[2])
 
+    def testPlaneRotateZNormal(self):
+        """
+        Rotation of a plane in the Z direction should never alter its normal.
+
+        This test creates random planes, with the normal in a random direction
+        among positive and negative X, Y and Z. The plane is defined with this
+        normal and another random perpendicular vector (the X-direction of the
+        plane). The plane is finally rotated a random angle in the Z-direction
+        to verify that the resulting plane maintains the same normal.
+        """
+        for _ in range(100):
+            normal_sign = choice((-1, 1))
+            normal_dir = randrange(3)
+            angle = (random() - 0.5) * 720
+
+            normal = [0, 0, 0]
+            normal[normal_dir] = normal_sign
+            xdir = [random(), random(), random()]
+            xdir[normal_dir] = 0
+
+            plane = Plane(origin=(0, 0, 0), xDir=xdir, normal=normal)
+            rotated = plane.rotated((0, 0, angle)).zDir.toTuple()
+            self.assertAlmostEqual(rotated[0], normal[0])
+            self.assertAlmostEqual(rotated[1], normal[1])
+            self.assertAlmostEqual(rotated[2], normal[2])
+
     def testLoft(self):
         """
             Test making a lofted solid