Issue #6697: Check that _PyUnicode_AsString() result is not NULL in textio.c
The bug may occurs if locale.getpreferredencoding() returns an encoding with a
surrogate (very unlikely!).
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index b039c2f..b659795 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -905,8 +905,11 @@
Py_CLEAR(self->encoding);
}
}
- if (self->encoding != NULL)
+ if (self->encoding != NULL) {
encoding = _PyUnicode_AsString(self->encoding);
+ if (encoding == NULL)
+ goto error;
+ }
else if (encoding != NULL) {
self->encoding = PyUnicode_FromString(encoding);
if (self->encoding == NULL)
@@ -935,6 +938,8 @@
self->writetranslate = (newline == NULL || newline[0] != '\0');
if (!self->readuniversal && self->readnl) {
self->writenl = _PyUnicode_AsString(self->readnl);
+ if (self->writenl == NULL)
+ goto error;
if (!strcmp(self->writenl, "\n"))
self->writenl = NULL;
}
@@ -2408,7 +2413,7 @@
Py_DECREF(res);
if (r < 0)
return NULL;
-
+
if (r > 0) {
Py_RETURN_NONE; /* stream already closed */
}