BUG: Prevent crash in poly1d.__eq__

Fixes #8760

2 files changed, 13 insertions, 0 deletions

diff --git a/numpy/lib/polynomial.py b/numpy/lib/polynomial.py
index f00d95b6c..6c0c11ac6 100644
--- a/numpy/lib/polynomial.py
+++ b/numpy/lib/polynomial.py
@@ -1199,11 +1199,15 @@ class poly1d(object):
     __rtruediv__ = __rdiv__
 
     def __eq__(self, other):
+        if not isinstance(other, poly1d):
+            return NotImplemented
         if self.coeffs.shape != other.coeffs.shape:
             return False
         return (self.coeffs == other.coeffs).all()
 
     def __ne__(self, other):
+        if not isinstance(other, poly1d):
+            return NotImplemented
         return not self.__eq__(other)
 
     def __setattr__(self, key, val):
diff --git a/numpy/lib/tests/test_polynomial.py b/numpy/lib/tests/test_polynomial.py
index 00dffd3d3..f1e4543bb 100644
--- a/numpy/lib/tests/test_polynomial.py
+++ b/numpy/lib/tests/test_polynomial.py
@@ -213,6 +213,15 @@ class TestDocs(TestCase):
         v = np.arange(1, 21)
         assert_almost_equal(np.poly(v), np.poly(np.diag(v)))
 
+    def test_poly_eq(self):
+        p = np.poly1d([1, 2, 3])
+        p2 = np.poly1d([1, 2, 4])
+        assert_equal(p == None, False)
+        assert_equal(p != None, True)
+        assert_equal(p == p, True)
+        assert_equal(p == p2, False)
+        assert_equal(p != p2, True)
+
 
 if __name__ == "__main__":
     run_module_suite()