bpo-35459: Use PyDict_GetItemWithError() instead of PyDict_GetItem()

Include/cpython/dictobject.h

@@ -35,6 +35,7 @@ PyAPI_FUNC(PyObject *) _PyDict_GetItem_KnownHash(PyObject *mp, PyObject *key,
                                        Py_hash_t hash);
 PyAPI_FUNC(PyObject *) _PyDict_GetItemIdWithError(PyObject *dp,
                                                   struct _Py_Identifier *key);
+PyAPI_FUNC(PyObject *) _PyDict_GetItemStringWithError(PyObject *, const char *);
 PyAPI_FUNC(PyObject *) PyDict_SetDefault(
     PyObject *mp, PyObject *key, PyObject *defaultobj);
 PyAPI_FUNC(int) _PyDict_SetItem_KnownHash(PyObject *mp, PyObject *key,

Modules/_csv.c

@@ -132,7 +132,7 @@ get_dialect_from_registry(PyObject * name_obj)
 {
     PyObject *dialect_obj;
 
-    dialect_obj = PyDict_GetItem(_csvstate_global->dialects, name_obj);
+    dialect_obj = PyDict_GetItemWithError(_csvstate_global->dialects, name_obj);
     if (dialect_obj == NULL) {
         if (!PyErr_Occurred())
             PyErr_Format(_csvstate_global->error_obj, "unknown dialect");
@@ -1434,8 +1434,12 @@ csv_register_dialect(PyObject *module, PyObject *args, PyObject *kwargs)
 static PyObject *
 csv_unregister_dialect(PyObject *module, PyObject *name_obj)
 {
-    if (PyDict_DelItem(_csvstate_global->dialects, name_obj) < 0)
-        return PyErr_Format(_csvstate_global->error_obj, "unknown dialect");
+    if (PyDict_DelItem(_csvstate_global->dialects, name_obj) < 0) {
+        if (PyErr_ExceptionMatches(PyExc_KeyError)) {
+            PyErr_Format(_csvstate_global->error_obj, "unknown dialect");
+        }
+        return NULL;
+    }
     Py_RETURN_NONE;
 }
 

Modules/_elementtree.c

@@ -339,7 +339,7 @@ get_attrib_from_keywords(PyObject *kwds)
     if (attrib_str == NULL) {
         return NULL;
     }
-    PyObject *attrib = PyDict_GetItem(kwds, attrib_str);
+    PyObject *attrib = PyDict_GetItemWithError(kwds, attrib_str);
 
     if (attrib) {
         /* If attrib was found in kwds, copy its value and remove it from
@@ -356,7 +356,8 @@ get_attrib_from_keywords(PyObject *kwds)
             Py_DECREF(attrib);
             attrib = NULL;
         }
-    } else {
+    }
+    else if (!PyErr_Occurred()) {
         attrib = PyDict_New();
     }
 
@@ -1393,9 +1394,13 @@ _elementtree_Element_get_impl(ElementObject *self, PyObject *key,
     if (!self->extra || self->extra->attrib == Py_None)
         value = default_value;
     else {
-        value = PyDict_GetItem(self->extra->attrib, key);
-        if (!value)
+        value = PyDict_GetItemWithError(self->extra->attrib, key);
+        if (!value) {
+            if (PyErr_Occurred()) {
+                return NULL;
+            }
             value = default_value;
+        }
     }
 
     Py_INCREF(value);
@@ -2848,11 +2853,12 @@ makeuniversal(XMLParserObject* self, const char* string)
     if (!key)
         return NULL;
 
-    value = PyDict_GetItem(self->names, key);
+    value = PyDict_GetItemWithError(self->names, key);
 
     if (value) {
         Py_INCREF(value);
-    } else {
+    }
+    else if (!PyErr_Occurred()) {
         /* new name.  convert to universal name, and decode as
            necessary */
 
@@ -2974,7 +2980,7 @@ expat_default_handler(XMLParserObject* self, const XML_Char* data_in,
     if (!key)
         return;
 
-    value = PyDict_GetItem(self->entity, key);
+    value = PyDict_GetItemWithError(self->entity, key);
 
     if (value) {
         if (TreeBuilder_CheckExact(self->target))

Modules/_json.c

@@ -746,12 +746,15 @@ _parse_object_unicode(PyScannerObject *s, PyObject *pystr, Py_ssize_t idx, Py_ss
             key = scanstring_unicode(pystr, idx + 1, s->strict, &next_idx);
             if (key == NULL)
                 goto bail;
-            memokey = PyDict_GetItem(s->memo, key);
+            memokey = PyDict_GetItemWithError(s->memo, key);
             if (memokey != NULL) {
                 Py_INCREF(memokey);
                 Py_DECREF(key);
                 key = memokey;
             }
+            else if (PyErr_Occurred()) {
+                goto bail;
+            }
             else {
                 if (PyDict_SetItem(s->memo, key, key) < 0)
                     goto bail;

Modules/_sre.c

@@ -1899,15 +1899,7 @@ match_getslice_by_index(MatchObject* self, Py_ssize_t index, PyObject* def)
     void* ptr;
     Py_ssize_t i, j;
 
-    if (index < 0 || index >= self->groups) {
-        /* raise IndexError if we were given a bad group number */
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
-        return NULL;
-    }
-
+    assert(0 <= index && index < self->groups);
     index *= 2;
 
     if (self->string == Py_None || self->mark[index] < 0) {
@@ -1940,25 +1932,39 @@ match_getindex(MatchObject* self, PyObject* index)
         return 0;
 
     if (PyIndex_Check(index)) {
-        return PyNumber_AsSsize_t(index, NULL);
+        i = PyNumber_AsSsize_t(index, NULL);
     }
+    else {
+        i = -1;
 
-    i = -1;
-
-    if (self->pattern->groupindex) {
-        index = PyDict_GetItem(self->pattern->groupindex, index);
-        if (index && PyLong_Check(index)) {
-            i = PyLong_AsSsize_t(index);
+        if (self->pattern->groupindex) {
+            index = PyDict_GetItemWithError(self->pattern->groupindex, index);
+            if (index && PyLong_Check(index)) {
+                i = PyLong_AsSsize_t(index);
+            }
         }
     }
+    if (i < 0 || i >= self->groups) {
+        /* raise IndexError if we were given a bad group number */
+        if (!PyErr_Occurred()) {
+            PyErr_SetString(PyExc_IndexError, "no such group");
+        }
+        return -1;
+    }
 
     return i;
 }
 
 static PyObject*
 match_getslice(MatchObject* self, PyObject* index, PyObject* def)
 {
-    return match_getslice_by_index(self, match_getindex(self, index), def);
+    Py_ssize_t i = match_getindex(self, index);
+
+    if (i < 0) {
+        return NULL;
+    }
+
+    return match_getslice_by_index(self, i, def);
 }
 
 /*[clinic input]
@@ -2114,11 +2120,7 @@ _sre_SRE_Match_start_impl(MatchObject *self, PyObject *group)
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
+    if (index < 0) {
         return -1;
     }
 
@@ -2141,11 +2143,7 @@ _sre_SRE_Match_end_impl(MatchObject *self, PyObject *group)
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
+    if (index < 0) {
         return -1;
     }
 
@@ -2195,11 +2193,7 @@ _sre_SRE_Match_span_impl(MatchObject *self, PyObject *group)
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
+    if (index < 0) {
         return NULL;
     }
 

Modules/_struct.c

@@ -2088,12 +2088,15 @@ cache_struct_converter(PyObject *fmt, PyStructObject **ptr)
             return 0;
     }
 
-    s_object = PyDict_GetItem(cache, fmt);
+    s_object = PyDict_GetItemWithError(cache, fmt);
     if (s_object != NULL) {
         Py_INCREF(s_object);
         *ptr = (PyStructObject *)s_object;
         return Py_CLEANUP_SUPPORTED;
     }
+    else if (PyErr_Occurred()) {
+        return 0;
+    }
 
     s_object = PyObject_CallFunctionObjArgs((PyObject *)(&PyStructType), fmt, NULL);
     if (s_object != NULL) {

Modules/_testmultiphase.c

@@ -53,11 +53,14 @@ static PyObject *
 Example_getattro(ExampleObject *self, PyObject *name)
 {
     if (self->x_attr != NULL) {
-        PyObject *v = PyDict_GetItem(self->x_attr, name);
+        PyObject *v = PyDict_GetItemWithError(self->x_attr, name);
         if (v != NULL) {
             Py_INCREF(v);
             return v;
         }
+        else if (PyErr_Occurred()) {
+            return NULL;
+        }
     }
     return PyObject_GenericGetAttr((PyObject *)self, name);
 }
@@ -72,7 +75,7 @@ Example_setattr(ExampleObject *self, const char *name, PyObject *v)
     }
     if (v == NULL) {
         int rv = PyDict_DelItemString(self->x_attr, name);
-        if (rv < 0)
+        if (rv < 0 && PyErr_ExceptionMatches(PyExc_KeyError))
             PyErr_SetString(PyExc_AttributeError,
                 "delete non-existing Example attribute");
         return rv;

Modules/_threadmodule.c

@@ -814,8 +814,11 @@ _ldict(localobject *self)
         return NULL;
     }
 
-    dummy = PyDict_GetItem(tdict, self->key);
+    dummy = PyDict_GetItemWithError(tdict, self->key);
     if (dummy == NULL) {
+        if (PyErr_Occurred()) {
+            return NULL;
+        }
         ldict = _local_create_dummy(self);
         if (ldict == NULL)
             return NULL;
@@ -931,14 +934,17 @@ local_getattro(localobject *self, PyObject *name)
             (PyObject *)self, name, ldict, 0);
 
     /* Optimization: just look in dict ourselves */
-    value = PyDict_GetItem(ldict, name);
-    if (value == NULL)
-        /* Fall back on generic to get __class__ and __dict__ */
-        return _PyObject_GenericGetAttrWithDict(
-            (PyObject *)self, name, ldict, 0);
-
-    Py_INCREF(value);
-    return value;
+    value = PyDict_GetItemWithError(ldict, name);
+    if (value != NULL) {
+        Py_INCREF(value);
+        return value;
+    }
+    else if (PyErr_Occurred()) {
+        return NULL;
+    }
+    /* Fall back on generic to get __class__ and __dict__ */
+    return _PyObject_GenericGetAttrWithDict(
+        (PyObject *)self, name, ldict, 0);
 }
 
 /* Called when a dummy is destroyed. */
@@ -958,7 +964,7 @@ _localdummy_destroyed(PyObject *localweakref, PyObject *dummyweakref)
     self = (localobject *) obj;
     if (self->dummies != NULL) {
         PyObject *ldict;
-        ldict = PyDict_GetItem(self->dummies, dummyweakref);
+        ldict = PyDict_GetItemWithError(self->dummies, dummyweakref);
         if (ldict != NULL) {
             PyDict_DelItem(self->dummies, dummyweakref);
         }

Modules/itertoolsmodule.c

@@ -4418,6 +4418,7 @@ static PyTypeObject ziplongest_type;
 static PyObject *
 zip_longest_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 {
+    _Py_IDENTIFIER(fillvalue);
     ziplongestobject *lz;
     Py_ssize_t i;
     PyObject *ittuple;  /* tuple of iterators */
@@ -4426,10 +4427,15 @@ zip_longest_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     Py_ssize_t tuplesize;
 
     if (kwds != NULL && PyDict_CheckExact(kwds) && PyDict_GET_SIZE(kwds) > 0) {
-        fillvalue = PyDict_GetItemString(kwds, "fillvalue");
-        if (fillvalue == NULL || PyDict_GET_SIZE(kwds) > 1) {
-            PyErr_SetString(PyExc_TypeError,
-                "zip_longest() got an unexpected keyword argument");
+        fillvalue = NULL;
+        if (PyDict_GET_SIZE(kwds) == 1) {
+            fillvalue = _PyDict_GetItemIdWithError(kwds, &PyId_fillvalue);
+        }
+        if (fillvalue == NULL) {
+            if (!PyErr_Occurred()) {
+                PyErr_SetString(PyExc_TypeError,
+                    "zip_longest() got an unexpected keyword argument");
+            }
             return NULL;
         }
     }

Modules/main.c

@@ -501,10 +501,14 @@ pymain_free(_PyMain *pymain)
 static int
 pymain_sys_path_add_path0(PyInterpreterState *interp, PyObject *path0)
 {
+    _Py_IDENTIFIER(path);
     PyObject *sys_path;
     PyObject *sysdict = interp->sysdict;
     if (sysdict != NULL) {
-        sys_path = PyDict_GetItemString(sysdict, "path");
+        sys_path = _PyDict_GetItemIdWithError(sysdict, &PyId_path);
+        if (sys_path == NULL && PyErr_Occurred()) {
+            goto error;
+        }
     }
     else {
         sys_path = NULL;

Modules/posixmodule.c

@@ -9830,6 +9830,9 @@ os_unsetenv_impl(PyObject *module, PyObject *name)
      */
     if (PyDict_DelItem(posix_putenv_garbage, name)) {
         /* really not much we can do; just leak */
+        if (!PyErr_ExceptionMatches(PyExc_KeyError)) {
+            return NULL;
+        }
         PyErr_Clear();
     }
     Py_RETURN_NONE;