Merge pull request #17817 from seberg/test-bad-array-like

BUG: Ignore fewer errors during array-coercion

numpy/core/src/multiarray/array_coercion.c

@@ -979,14 +979,28 @@ PyArray_DiscoverDTypeAndShape_Recursive(
      * and to handle it recursively. That is, unless we have hit the
      * dimension limit.
      */
-    npy_bool is_sequence = (PySequence_Check(obj) && PySequence_Size(obj) >= 0);
+    npy_bool is_sequence = PySequence_Check(obj);
+    if (is_sequence) {
+        is_sequence = PySequence_Size(obj) >= 0;
+        if (NPY_UNLIKELY(!is_sequence)) {
+            /* NOTE: This should likely just raise all errors */
+            if (PyErr_ExceptionMatches(PyExc_RecursionError) ||
+                    PyErr_ExceptionMatches(PyExc_MemoryError)) {
+                /*
+                 * Consider these unrecoverable errors, continuing execution
+                 * might crash the interpreter.
+                 */
+                return -1;
+            }
+            PyErr_Clear();
+        }
+    }
     if (NPY_UNLIKELY(*flags & DISCOVER_TUPLES_AS_ELEMENTS) &&
             PyTuple_Check(obj)) {
         is_sequence = NPY_FALSE;
     }
     if (curr_dims == max_dims || !is_sequence) {
         /* Clear any PySequence_Size error which would corrupts further calls */
-        PyErr_Clear();
         max_dims = handle_scalar(
                 obj, curr_dims, &max_dims, out_descr, out_shape, fixed_DType,
                 flags, NULL);

numpy/core/src/multiarray/ctors.c

@@ -2124,7 +2124,7 @@ PyArray_FromInterface(PyObject *origin)
 
     if (iface == NULL) {
         if (PyErr_Occurred()) {
-            PyErr_Clear(); /* TODO[gh-14801]: propagate crashes during attribute access? */
+            return NULL;
         }
         return Py_NotImplemented;
     }
@@ -2392,7 +2392,7 @@ PyArray_FromArrayAttr(PyObject *op, PyArray_Descr *typecode, PyObject *context)
     array_meth = PyArray_LookupSpecial_OnInstance(op, "__array__");
     if (array_meth == NULL) {
         if (PyErr_Occurred()) {
-            PyErr_Clear(); /* TODO[gh-14801]: propagate crashes during attribute access? */
+            return NULL;
         }
         return Py_NotImplemented;
     }

numpy/core/tests/test_array_coercion.py

@@ -689,3 +689,33 @@ def test_too_large_array_error_paths(self):
                 np.array(arr)
             with pytest.raises(MemoryError):
                 np.array([arr])
+
+    @pytest.mark.parametrize("attribute",
+        ["__array_interface__", "__array__", "__array_struct__"])
+    def test_bad_array_like_attributes(self, attribute):
+        # Check that errors during attribute retrieval are raised unless
+        # they are Attribute errors.
+
+        class BadInterface:
+            def __getattr__(self, attr):
+                if attr == attribute:
+                    raise RuntimeError
+                super().__getattr__(attr)
+
+        with pytest.raises(RuntimeError):
+            np.array(BadInterface())
+
+    @pytest.mark.parametrize("error", [RecursionError, MemoryError])
+    def test_bad_array_like_bad_length(self, error):
+        # RecursionError and MemoryError are considered "critical" in
+        # sequences. We could expand this more generally though. (NumPy 1.20)
+        class BadSequence:
+            def __len__(self):
+                raise error
+            def __getitem__(self):
+                # must have getitem to be a Sequence
+                return 1
+
+        with pytest.raises(error):
+            np.array(BadSequence())
+