[3.8] bpo-37994: Fix silencing all errors if an attribute lookup fails. (GH-15630) (GH-15635)

Only AttributeError should be silenced.
(cherry picked from commit 41c57b335330ff48af098d47e379e0f9ba09d233)

5 files changed, 28 insertions, 22 deletions

diff --git a/Modules/_csv.c b/Modules/_csv.c
index 014cbb4..46d4143 100644
--- a/Modules/_csv.c
+++ b/Modules/_csv.c
@@ -1382,7 +1382,10 @@ csv_writer(PyObject *module, PyObject *args, PyObject *keyword_args)
         Py_DECREF(self);
         return NULL;
     }
-    self->write = _PyObject_GetAttrId(output_file, &PyId_write);
+    if (_PyObject_LookupAttrId(output_file, &PyId_write, &self->write) < 0) {
+        Py_DECREF(self);
+        return NULL;
+    }
     if (self->write == NULL || !PyCallable_Check(self->write)) {
         PyErr_SetString(PyExc_TypeError,
                         "argument 1 must have a \"write\" method");
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index d3c3f09..41c3f34 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -3610,24 +3610,24 @@ tzinfo_reduce(PyObject *self, PyObject *Py_UNUSED(ignored))
     _Py_IDENTIFIER(__getinitargs__);
     _Py_IDENTIFIER(__getstate__);
 
-    getinitargs = _PyObject_GetAttrId(self, &PyId___getinitargs__);
+    if (_PyObject_LookupAttrId(self, &PyId___getinitargs__, &getinitargs) < 0) {
+        return NULL;
+    }
     if (getinitargs != NULL) {
         args = _PyObject_CallNoArg(getinitargs);
         Py_DECREF(getinitargs);
-        if (args == NULL) {
-            return NULL;
-        }
     }
     else {
-        PyErr_Clear();
-
         args = PyTuple_New(0);
-        if (args == NULL) {
-            return NULL;
-        }
+    }
+    if (args == NULL) {
+        return NULL;
     }
 
-    getstate = _PyObject_GetAttrId(self, &PyId___getstate__);
+    if (_PyObject_LookupAttrId(self, &PyId___getstate__, &getstate) < 0) {
+        Py_DECREF(args);
+        return NULL;
+    }
     if (getstate != NULL) {
         state = _PyObject_CallNoArg(getstate);
         Py_DECREF(getstate);
@@ -3638,7 +3638,6 @@ tzinfo_reduce(PyObject *self, PyObject *Py_UNUSED(ignored))
     }
     else {
         PyObject **dictptr;
-        PyErr_Clear();
         state = Py_None;
         dictptr = _PyObject_GetDictPtr(self);
         if (dictptr && *dictptr && PyDict_GET_SIZE(*dictptr)) {
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index bbe2603..fa2ef7d 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -4385,7 +4385,6 @@ save(PicklerObject *self, PyObject *obj, int pers_save)
         _Py_IDENTIFIER(__reduce__);
         _Py_IDENTIFIER(__reduce_ex__);
 
-
         /* XXX: If the __reduce__ method is defined, __reduce_ex__ is
            automatically defined as __reduce__. While this is convenient, this
            make it impossible to know which method was actually called. Of
@@ -4406,14 +4405,15 @@ save(PicklerObject *self, PyObject *obj, int pers_save)
             }
         }
         else {
-            PickleState *st = _Pickle_GetGlobalState();
-
             /* Check for a __reduce__ method. */
-            reduce_func = _PyObject_GetAttrId(obj, &PyId___reduce__);
+            if (_PyObject_LookupAttrId(obj, &PyId___reduce__, &reduce_func) < 0) {
+                goto error;
+            }
             if (reduce_func != NULL) {
                 reduce_value = _PyObject_CallNoArg(reduce_func);
             }
             else {
+                PickleState *st = _Pickle_GetGlobalState();
                 PyErr_Format(st->PicklingError,
                              "can't pickle '%.200s' object: %R",
                              type->tp_name, obj);
@@ -6448,7 +6448,9 @@ do_append(UnpicklerObject *self, Py_ssize_t x)
         PyObject *extend_func;
         _Py_IDENTIFIER(extend);
 
-        extend_func = _PyObject_GetAttrId(list, &PyId_extend);
+        if (_PyObject_LookupAttrId(list, &PyId_extend, &extend_func) < 0) {
+            return -1;
+        }
         if (extend_func != NULL) {
             slice = Pdata_poplist(self->stack, x);
             if (!slice) {
@@ -6468,7 +6470,6 @@ do_append(UnpicklerObject *self, Py_ssize_t x)
             /* Even if the PEP 307 requires extend() and append() methods,
                fall back on append() if the object has no extend() method
                for backward compatibility. */
-            PyErr_Clear();
             append_func = _PyObject_GetAttrId(list, &PyId_append);
             if (append_func == NULL)
                 return -1;
diff --git a/Modules/_threadmodule.c b/Modules/_threadmodule.c
index d5e40ef..fadf57a 100644
--- a/Modules/_threadmodule.c
+++ b/Modules/_threadmodule.c
@@ -1305,6 +1305,7 @@ static int
 thread_excepthook_file(PyObject *file, PyObject *exc_type, PyObject *exc_value,
                        PyObject *exc_traceback, PyObject *thread)
 {
+    _Py_IDENTIFIER(name);
     /* print(f"Exception in thread {thread.name}:", file=file) */
     if (PyFile_WriteString("Exception in thread ", file) < 0) {
         return -1;
@@ -1312,7 +1313,9 @@ thread_excepthook_file(PyObject *file, PyObject *exc_type, PyObject *exc_value,
 
     PyObject *name = NULL;
     if (thread != Py_None) {
-        name = PyObject_GetAttrString(thread, "name");
+        if (_PyObject_LookupAttrId(thread, &PyId_name, &name) < 0) {
+            return -1;
+        }
     }
     if (name != NULL) {
         if (PyFile_WriteObject(name, file, Py_PRINT_RAW) < 0) {
@@ -1322,8 +1325,6 @@ thread_excepthook_file(PyObject *file, PyObject *exc_type, PyObject *exc_value,
         Py_DECREF(name);
     }
     else {
-        PyErr_Clear();
-
         unsigned long ident = PyThread_get_thread_ident();
         PyObject *str = PyUnicode_FromFormat("%lu", ident);
         if (str != NULL) {
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 45a1e68..bb5e25c 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -810,7 +810,9 @@ pyexpat_xmlparser_ParseFile(xmlparseobject *self, PyObject *file)
     PyObject *readmethod = NULL;
     _Py_IDENTIFIER(read);
 
-    readmethod = _PyObject_GetAttrId(file, &PyId_read);
+    if (_PyObject_LookupAttrId(file, &PyId_read, &readmethod) < 0) {
+        return NULL;
+    }
     if (readmethod == NULL) {
         PyErr_SetString(PyExc_TypeError,
                         "argument must have 'read' attribute");