Removes malformed fast path for zero-size arrays in repeat (#1682)

* Removes malformed fast path for size-zero arrays in `repeat`

* Adds a test for fixed behavior of `repeat` with 0-size arrays

Author: ndgrigorian

dpctl/tensor/_manipulation_functions.py

@@ -838,9 +838,6 @@ def repeat(x, repeats, /, *, axis=None):
             f"got {type(repeats)}"
         )
 
-    if axis_size == 0:
-        return dpt.empty(x_shape, dtype=x.dtype, sycl_queue=exec_q)
-
     if scalar:
         res_axis_size = repeats * axis_size
         if axis is not None:

dpctl/tests/test_usm_ndarray_manipulation.py

@@ -1485,3 +1485,35 @@ def test_tile_arg_validation():
     x = dpt.empty(())
     with pytest.raises(TypeError):
         dpt.tile(x, dict())
+
+
+def test_repeat_0_size():
+    get_queue_or_skip()
+
+    x = dpt.ones((0, 10, 0), dtype="i4")
+    repetitions = 2
+    res = dpt.repeat(x, repetitions)
+    assert res.shape == (0,)
+    res = dpt.repeat(x, repetitions, axis=2)
+    assert res.shape == x.shape
+    res = dpt.repeat(x, repetitions, axis=1)
+    axis_sz = x.shape[1] * repetitions
+    assert res.shape == (0, 20, 0)
+
+    repetitions = dpt.asarray(2, dtype="i4")
+    res = dpt.repeat(x, repetitions)
+    assert res.shape == (0,)
+    res = dpt.repeat(x, repetitions, axis=2)
+    assert res.shape == x.shape
+    res = dpt.repeat(x, repetitions, axis=1)
+    assert res.shape == (0, 20, 0)
+
+    repetitions = dpt.arange(10, dtype="i4")
+    res = dpt.repeat(x, repetitions, axis=1)
+    axis_sz = dpt.sum(repetitions)
+    assert res.shape == (0, axis_sz, 0)
+
+    repetitions = (2,) * 10
+    res = dpt.repeat(x, repetitions, axis=1)
+    axis_sz = 2 * x.shape[1]
+    assert res.shape == (0, axis_sz, 0)