Merge pull request #22970 from charris/backport-22959

BUG: Fix fill violating read-only flag. (#22959)
numpy · Jan 9, 2023 · d979064 · d979064
2 parents 5c0f8fe + 35d879c
commit d979064
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diff --git a/numpy/core/src/multiarray/convert.c b/numpy/core/src/multiarray/convert.c
@@ -359,6 +359,11 @@ PyArray_ToString(PyArrayObject *self, NPY_ORDER order)
 NPY_NO_EXPORT int
 PyArray_FillWithScalar(PyArrayObject *arr, PyObject *obj)
 {
+
+    if (PyArray_FailUnlessWriteable(arr, "assignment destination") < 0) {
+        return -1;
+    }
+
     /*
      * If we knew that the output array has at least one element, we would
      * not actually need a helping buffer, we always null it, just in case.

diff --git a/numpy/core/tests/test_multiarray.py b/numpy/core/tests/test_multiarray.py
@@ -403,6 +403,13 @@ def test_fill_struct_array(self):
         assert_array_equal(x['a'], [3.5, 3.5])
         assert_array_equal(x['b'], [-2, -2])
 
+    def test_fill_readonly(self):
+        # gh-22922
+        a = np.zeros(11)
+        a.setflags(write=False)
+        with pytest.raises(ValueError, match=".*read-only"):
+            a.fill(0)
+
 
 class TestArrayConstruction:
     def test_array(self):