BUG: Fix missing check for PyErr_Occurred() in _pyarray_correlate. (#28898)

hawkinsp · charris · commit bd1c863f4a17 · 2025-05-06T15:09:10.000-06:00
When running the scipy 1.15 test suite test
signal/tests/test_signaltools.py::test_lfilter_bad_object, with Python
built in debug mode, we see the following error:

```
Fatal Python error: _Py_CheckSlotResult: Slot * of type float succeeded with an exception set
```

`None` ends up as the first argument to `dot`, and this triggers an
error from PyFloat_Multiply. Once an error has occurred, we must avoid
calling multiply again, since it asserts that PyErr_Occurred() is false
if the output is a non-error, which will fail if an error was set at
entry.
diff --git a/numpy/_core/src/multiarray/multiarraymodule.c b/numpy/_core/src/multiarray/multiarraymodule.c
@@ -1215,6 +1215,7 @@ _pyarray_correlate(PyArrayObject *ap1, PyArrayObject *ap2, int typenum,
         goto clean_ret;
     }
 
+    int needs_pyapi = PyDataType_FLAGCHK(PyArray_DESCR(ret), NPY_NEEDS_PYAPI);
     NPY_BEGIN_THREADS_DESCR(PyArray_DESCR(ret));
     is1 = PyArray_STRIDES(ap1)[0];
     is2 = PyArray_STRIDES(ap2)[0];
@@ -1225,6 +1226,9 @@ _pyarray_correlate(PyArrayObject *ap1, PyArrayObject *ap2, int typenum,
     n = n - n_left;
     for (i = 0; i < n_left; i++) {
         dot(ip1, is1, ip2, is2, op, n, ret);
+        if (needs_pyapi && PyErr_Occurred()) {
+            goto done;
+        }
         n++;
         ip2 -= is2;
         op += os;
@@ -1236,19 +1240,21 @@ _pyarray_correlate(PyArrayObject *ap1, PyArrayObject *ap2, int typenum,
         op += os * (n1 - n2 + 1);
     }
     else {
-        for (i = 0; i < (n1 - n2 + 1); i++) {
+        for (i = 0; i < (n1 - n2 + 1) && (!needs_pyapi || !PyErr_Occurred());
+             i++) {
             dot(ip1, is1, ip2, is2, op, n, ret);
             ip1 += is1;
             op += os;
         }
     }
-    for (i = 0; i < n_right; i++) {
+    for (i = 0; i < n_right && (!needs_pyapi || !PyErr_Occurred()); i++) {
         n--;
         dot(ip1, is1, ip2, is2, op, n, ret);
         ip1 += is1;
         op += os;
     }
 
+done:
     NPY_END_THREADS_DESCR(PyArray_DESCR(ret));
     if (PyErr_Occurred()) {
         goto clean_ret;
