imp.find_module('test/badsyntax_pep3120') causes segfault

Python/traceback.c

 
 /* Traceback implementation */
 
 #include "Python.h"
 
 #include "code.h"
 #include "frameobject.h"
 #include "structmember.h"
 #include "osdefs.h"
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
 
 #define OFF(x) offsetof(PyTracebackObject, x)
-
-/* Method from Parser/tokenizer.c */
-extern char * PyTokenizer_FindEncoding(int);
 
 static PyObject *
 tb_dir(PyTracebackObject *self)
 {
     return Py_BuildValue("[ssss]", "tb_frame", "tb_next",
                                    "tb_lasti", "tb_lineno");
 }
 
 static PyMethodDef tb_methods[] = {
    {"__dir__", (PyCFunction)tb_dir, METH_NOARGS},
@@ skipping 191 matching lines @@
     char *found_encoding;
     char *encoding;
     PyObject *io;
     PyObject *binary;
     PyObject *fob = NULL;
     PyObject *lineobj = NULL;
     PyObject *res;
     char buf[MAXPATHLEN+1];
     Py_UNICODE *u, *p;
     Py_ssize_t len;
+    char *filename_utf8;
 
     /* open the file */
     if (filename == NULL)
         return 0;
 
     io = PyImport_ImportModuleNoBlock("io");
     if (io == NULL)
         return -1;
     binary = PyObject_CallMethod(io, "open", "Os", filename, "rb");
 
     if (binary == NULL) {
         binary = _Py_FindSourceFile(filename, buf, sizeof(buf), io);
         if (binary == NULL) {
             Py_DECREF(io);
             return 0;
         }
     }
 
     /* use the right encoding to decode the file as unicode */
     fd = PyObject_AsFileDescriptor(binary);
-    found_encoding = PyTokenizer_FindEncoding(fd);
+    filename_utf8 = _PyUnicode_AsString(filename);
+    if (filename_utf8 == NULL)
+        PyErr_Clear();
+    found_encoding = PyTokenizer_FindEncodingFilename(fd, filename_utf8);
     encoding = (found_encoding != NULL) ? found_encoding : "utf-8";
     lseek(fd, 0, 0); /* Reset position */
     fob = PyObject_CallMethod(io, "TextIOWrapper", "Os", binary, encoding);
     Py_DECREF(io);
     Py_DECREF(binary);
     PyMem_FREE(found_encoding);
 
     if (fob == NULL) {
         PyErr_Clear();
         return 0;
@@ skipping 135 matching lines @@
         else if (limit <= 0) {
             limit = PyTraceBack_LIMIT;
         }
         PyErr_Restore(exc_type, exc_value, exc_tb);
     }
     err = PyFile_WriteString("Traceback (most recent call last):\n", f);
     if (!err)
         err = tb_printinternal((PyTracebackObject *)v, f, limit);
     return err;
 }