fix some cases where errors in IsInstance()/IsSubtype() calls were not handled

CHANGES.rst

@@ -10,6 +10,9 @@ Bugs fixed
 
 * Crash when returning values on generator termination.
 
+* In some cases, exceptions raised during internal isinstance() checks were
+  not propagated.
+
 * Runtime reported file paths of source files (e.g for profiling and tracing)
   are now relative to the build root directory instead of the main source file.
 

Cython/Utility/CythonFunction.c

@@ -1017,13 +1017,17 @@ __pyx_FusedFunction_call(PyObject *func, PyObject *args, PyObject *kw)
         self = PyTuple_GET_ITEM(args, 0);
     }
 
-    if (self && !is_classmethod && !is_staticmethod &&
-            !PyObject_IsInstance(self, binding_func->type)) {
+    if (self && !is_classmethod && !is_staticmethod) {
+        int is_instance = PyObject_IsInstance(self, binding_func->type);
+        if (unlikely(!is_instance)) {
             PyErr_Format(PyExc_TypeError,
                          "First argument should be of type %.200s, got %.200s.",
                          ((PyTypeObject *) binding_func->type)->tp_name,
                          self->ob_type->tp_name);
             goto __pyx_err;
+        } else if (unlikely(is_instance == -1)) {
+            goto __pyx_err;
+        }
     }
 
     if (binding_func->__signatures__) {

Cython/Utility/Exceptions.c

@@ -144,11 +144,15 @@ static void __Pyx_Raise(PyObject *type, PyObject *value, PyObject *tb, PyObject
         if (value && PyExceptionInstance_Check(value)) {
             instance_class = (PyObject*) Py_TYPE(value);
             if (instance_class != type) {
-                if (PyObject_IsSubclass(instance_class, type)) {
+                int is_subclass = PyObject_IsSubclass(instance_class, type);
+                if (!is_subclass) {
+                    instance_class = NULL;
+                } else if (unlikely(is_subclass == -1)) {
+                    // error on subclass test
+                    goto bad;
+                } else {
                     // believe the instance
                     type = instance_class;
-                } else {
-                    instance_class = NULL;
                 }
             }
         }

Cython/Utility/Generator.c

@@ -102,6 +102,7 @@ static PyTypeObject *__pyx_GeneratorType = 0;
 static int __Pyx_PyGen_FetchStopIterationValue(PyObject **pvalue) {
     PyObject *et, *ev, *tb;
     PyObject *value = NULL;
+    int result;
 
     __Pyx_ErrFetch(&et, &ev, &tb);
 
@@ -121,7 +122,8 @@ static int __Pyx_PyGen_FetchStopIterationValue(PyObject **pvalue) {
 
     // most common case: plain StopIteration without or with separate argument
     if (likely(et == PyExc_StopIteration)) {
-        if (likely(!ev) || !PyObject_IsInstance(ev, PyExc_StopIteration)) {
+        int error = 0;
+        if (!ev || !(error = PyObject_IsInstance(ev, PyExc_StopIteration))) {
             // PyErr_SetObject() and friends put the value directly into ev
             if (!ev) {
                 Py_INCREF(Py_None);
@@ -132,16 +134,26 @@ static int __Pyx_PyGen_FetchStopIterationValue(PyObject **pvalue) {
             *pvalue = ev;
             return 0;
         }
+        if (unlikely(error == -1)) {
+            // error during isinstance() check
+            return -1;
+        }
     }
     // otherwise: normalise and check what that gives us
     PyErr_NormalizeException(&et, &ev, &tb);
-    if (unlikely(!PyObject_IsInstance(ev, PyExc_StopIteration))) {
+    result = PyObject_IsInstance(ev, PyExc_StopIteration);
+    if (unlikely(!result)) {
         // looks like normalisation failed - raise the new exception
         __Pyx_ErrRestore(et, ev, tb);
         return -1;
     }
     Py_XDECREF(tb);
     Py_DECREF(et);
+    if (unlikely(result == -1)) {
+        // error during isinstance() check
+        Py_DECREF(ev);
+        return -1;
+    }
 #if PY_VERSION_HEX >= 0x030300A0
     value = ((PyStopIterationObject *)ev)->value;
     Py_INCREF(value);

Cython/Utility/ObjectHandling.c

@@ -1415,6 +1415,8 @@ bad:
 
 static PyObject* __Pyx__PyNumber_MatrixMultiply(PyObject* x, PyObject* y, const char* op_name) {
     int right_is_subtype = PyObject_IsSubclass((PyObject*)Py_TYPE(y), (PyObject*)Py_TYPE(x));
+    if (unlikely(right_is_subtype == -1))
+        return NULL;
     if (right_is_subtype) {
         // to allow subtypes to override parent behaviour, try reversed operation first
         // see note at https://docs.python.org/3/reference/datamodel.html#emulating-numeric-types