Merge pull request #9624 from ExpHP/dot-memory-leak

BUG: memory leak in np.dot of size 0

2 files changed, 13 insertions, 1 deletions

diff --git a/numpy/core/src/multiarray/cblasfuncs.c b/numpy/core/src/multiarray/cblasfuncs.c
index 3b0b2f4f6..8432ae5cf 100644
--- a/numpy/core/src/multiarray/cblasfuncs.c
+++ b/numpy/core/src/multiarray/cblasfuncs.c
@@ -456,7 +456,8 @@ cblas_matrixproduct(int typenum, PyArrayObject *ap1, PyArrayObject *ap2,
     if (numbytes == 0 || l == 0) {
             Py_DECREF(ap1);
             Py_DECREF(ap2);
-            return PyArray_Return(out_buf);
+            Py_DECREF(out_buf);
+            return PyArray_Return(result);
     }
 
     if (ap2shape == _scalar) {
diff --git a/numpy/core/tests/test_multiarray.py b/numpy/core/tests/test_multiarray.py
index ba4b0e0d8..74f6a3af9 100644
--- a/numpy/core/tests/test_multiarray.py
+++ b/numpy/core/tests/test_multiarray.py
@@ -2497,6 +2497,17 @@ class TestMethods(object):
         if HAS_REFCOUNT:
             assert_(sys.getrefcount(a) < 50)
 
+    def test_size_zero_memleak(self):
+        # Regression test for issue 9615
+        # Exercises a special-case code path for dot products of length
+        # zero in cblasfuncs (making it is specific to floating dtypes).
+        a = np.array([], dtype=np.float64)
+        x = np.array(2.0)
+        for _ in range(100):
+            np.dot(a, a, out=x)
+        if HAS_REFCOUNT:
+            assert_(sys.getrefcount(x) < 50)
+
     def test_trace(self):
         a = np.arange(12).reshape((3, 4))
         assert_equal(a.trace(), 15)