Correctly merging #9319 into 3.3?

Lib/test/test_imp.py

@@ -176,6 +176,10 @@ class ImportTests(unittest.TestCase):
                 support.unlink(init_file_name + ext)
             support.rmtree(test_package_name)
 
+    def test_issue9319(self):
+        self.assertRaises(SyntaxError,
+                          imp.find_module, "test/badsyntax_pep3120")
+
 
 class ReloadTests(unittest.TestCase):
 

Parser/tokenizer.c

@@ -585,12 +585,19 @@ decoding_fgets(char *s, int size, struct tok_state *tok)
     if (badchar) {
         /* Need to add 1 to the line number, since this line
            has not been counted, yet.  */
-        PyErr_Format(PyExc_SyntaxError,
-                "Non-UTF-8 code starting with '\\x%.2x' "
-                "in file %U on line %i, "
-                "but no encoding declared; "
-                "see http://python.org/dev/peps/pep-0263/ for details",
-                badchar, tok->filename, tok->lineno + 1);
+        if (tok->filename != NULL)
+            filename = PyUnicode_DecodeFSDefault(tok->filename);
+        else
+            filename = PyUnicode_FromString("<file>");
+        if (filename != NULL) {
+            PyErr_Format(PyExc_SyntaxError,
+                    "Non-UTF-8 code starting with '\\x%.2x' "
+                    "in file %U on line %i, "
+                    "but no encoding declared; "
+                    "see http://python.org/dev/peps/pep-0263/ for details",
+                    badchar, filename, tok->lineno + 1);
+            Py_DECREF(filename);
+        }
         return error_ret(tok);
     }
 #endif