Fix issue 3221 by emitting a RuntimeWarning instead of raising SystemError when the parent module can't be found during an absolute import (likely due to non-PEP 361 aware code which sets a module level __package__ attribute)
diff --git a/Python/import.c b/Python/import.c
index b65ed0e..f0ee40a 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -2160,6 +2160,7 @@
static PyObject *pathstr = NULL;
static PyObject *pkgstr = NULL;
PyObject *pkgname, *modname, *modpath, *modules, *parent;
+ int orig_level = level;
if (globals == NULL || !PyDict_Check(globals) || !level)
return Py_None;
@@ -2285,9 +2286,27 @@
modules = PyImport_GetModuleDict();
parent = PyDict_GetItemString(modules, buf);
- if (parent == NULL)
- PyErr_Format(PyExc_SystemError,
- "Parent module '%.200s' not loaded", buf);
+ if (parent == NULL) {
+ if (orig_level < 1) {
+ PyObject *err_msg = PyString_FromFormat(
+ "Parent module '%.200s' not found "
+ "while handling absolute import", buf);
+ if (err_msg == NULL) {
+ return NULL;
+ }
+ if (!PyErr_WarnEx(PyExc_RuntimeWarning,
+ PyString_AsString(err_msg), 1)) {
+ *buf = '\0';
+ *p_buflen = 0;
+ parent = Py_None;
+ }
+ Py_DECREF(err_msg);
+ } else {
+ PyErr_Format(PyExc_SystemError,
+ "Parent module '%.200s' not loaded, "
+ "cannot perform relative import", buf);
+ }
+ }
return parent;
/* We expect, but can't guarantee, if parent != None, that:
- parent.__name__ == buf