commit cdd8d4d6dd57f4c9429566706009d4613277d391
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Mon Mar 25 14:36:43 2019 -0700
committer Stefan Krah <skrah@bytereef.org> Mon Mar 25 22:36:43 2019 +0100
tree ef8ff48e6365df8353edb58c1bf3e7a902e33b25
parent f3c5535f63e7cd49166ab33b7b0ebb3285ef4ed0

bpo-36370: Check for PyErr_Occurred() after PyImport_GetModule() (GH-12504)

Python/ceval.c

diff --git a/Python/ceval.c b/Python/ceval.c
index c394b9b..634edba 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -4816,7 +4816,7 @@
     }
     x = PyImport_GetModule(fullmodname);
     Py_DECREF(fullmodname);
-    if (x == NULL) {
+    if (x == NULL && !PyErr_Occurred()) {
         goto error;
     }
     Py_DECREF(pkgname);
@@ -4839,7 +4839,7 @@
             "cannot import name %R from %R (unknown location)",
             name, pkgname_or_unknown
         );
-        /* NULL check for errmsg done by PyErr_SetImportError. */
+        /* NULL checks for errmsg and pkgname done by PyErr_SetImportError. */
         PyErr_SetImportError(errmsg, pkgname, NULL);
     }
     else {
@@ -4847,7 +4847,7 @@
             "cannot import name %R from %R (%S)",
             name, pkgname_or_unknown, pkgpath
         );
-        /* NULL check for errmsg done by PyErr_SetImportError. */
+        /* NULL checks for errmsg and pkgname done by PyErr_SetImportError. */
         PyErr_SetImportError(errmsg, pkgname, pkgpath);
     }
 

Python/import.c

diff --git a/Python/import.c b/Python/import.c
index ccdd599..63c99ea 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -953,11 +953,10 @@
     Py_DECREF(v);
 
     m = PyImport_GetModule(name);
-    if (m == NULL) {
+    if (m == NULL && !PyErr_Occurred()) {
         PyErr_Format(PyExc_ImportError,
                      "Loaded module %R not found in sys.modules",
                      name);
-        return NULL;
     }
 
     return m;
@@ -1714,6 +1713,10 @@
     }
 
     mod = PyImport_GetModule(abs_name);
+    if (mod == NULL && PyErr_Occurred()) {
+        goto error;
+    }
+
     if (mod != NULL && mod != Py_None) {
         _Py_IDENTIFIER(__spec__);
         _Py_IDENTIFIER(_initializing);
@@ -1801,9 +1804,11 @@
                 final_mod = PyImport_GetModule(to_return);
                 Py_DECREF(to_return);
                 if (final_mod == NULL) {
-                    PyErr_Format(PyExc_KeyError,
-                                 "%R not in sys.modules as expected",
-                                 to_return);
+                    if (!PyErr_Occurred()) {
+                        PyErr_Format(PyExc_KeyError,
+                                     "%R not in sys.modules as expected",
+                                     to_return);
+                    }
                     goto error;
                 }
             }
@@ -1855,6 +1860,10 @@
     PyObject *reloaded_module = NULL;
     PyObject *imp = _PyImport_GetModuleId(&PyId_imp);
     if (imp == NULL) {
+        if (PyErr_Occurred()) {
+            return NULL;
+        }
+
         imp = PyImport_ImportModule("imp");
         if (imp == NULL) {
             return NULL;

Python/pylifecycle.c

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 94b6d43..d8e6f8f 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -2239,8 +2239,10 @@
     PyObject *result;
     PyObject *threading = _PyImport_GetModuleId(&PyId_threading);
     if (threading == NULL) {
-        /* threading not imported */
-        PyErr_Clear();
+        if (PyErr_Occurred()) {
+            PyErr_WriteUnraisable(NULL);
+        }
+        /* else: threading not imported */
         return;
     }
     result = _PyObject_CallMethodId(threading, &PyId__shutdown, NULL);

Python/sysmodule.c

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index c01a04e..d87b4e2 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -274,7 +274,9 @@
 
     builtins = _PyImport_GetModuleId(&PyId_builtins);
     if (builtins == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "lost builtins module");
+        if (!PyErr_Occurred()) {
+            PyErr_SetString(PyExc_RuntimeError, "lost builtins module");
+        }
         return NULL;
     }
     Py_DECREF(builtins);