BUG: Fix tiling of zero-sized arrays numpy/numpy#6089 and add test case.

2 files changed, 13 insertions, 10 deletions

diff --git a/numpy/lib/shape_base.py b/numpy/lib/shape_base.py
index 280765df8..26c2aab04 100644
--- a/numpy/lib/shape_base.py
+++ b/numpy/lib/shape_base.py
@@ -857,16 +857,16 @@ def tile(A, reps):
         # numpy array and the repetitions are 1 in all dimensions
         return _nx.array(A, copy=True, subok=True, ndmin=d)
     else:
+        # Note that no copy of zero-sized arrays is made. However since they
+        # have no data there is no risk of an inadvertent overwrite.
         c = _nx.array(A, copy=False, subok=True, ndmin=d)
-    shape = list(c.shape)
-    n = max(c.size, 1)
     if (d < c.ndim):
         tup = (1,)*(c.ndim-d) + tup
-    for i, nrep in enumerate(tup):
-        if nrep != 1:
-            c = c.reshape(-1, n).repeat(nrep, 0)
-        dim_in = shape[i]
-        dim_out = dim_in*nrep
-        shape[i] = dim_out
-        n //= max(dim_in, 1)
-    return c.reshape(shape)
+    shape_out = tuple(s*t for s, t in zip(c.shape, tup))
+    n = c.size
+    if n > 0:
+        for dim_in, nrep in zip(c.shape, tup):
+            if nrep != 1:
+                c = c.reshape(-1, n).repeat(nrep, 0)
+            n //= dim_in
+    return c.reshape(shape_out)
diff --git a/numpy/lib/tests/test_shape_base.py b/numpy/lib/tests/test_shape_base.py
index fb9d7f364..3f2d8d5b4 100644
--- a/numpy/lib/tests/test_shape_base.py
+++ b/numpy/lib/tests/test_shape_base.py
@@ -332,7 +332,10 @@ class TestTile(TestCase):
 
     def test_empty(self):
         a = np.array([[[]]])
+        b = np.array([[], []])
+        c = tile(b, 2).shape
         d = tile(a, (3, 2, 5)).shape
+        assert_equal(c, (2, 0))
         assert_equal(d, (3, 2, 0))
 
     def test_kroncompare(self):