commit 656207645485295477411224fdf41cfd4d598a88
author Krzysztof Blazewicz <krzysztof.blazewicz@uxeon.com> Sat Aug 20 13:45:25 2016 +0200
committer Paul Sokolovsky <pfalcon@users.sourceforge.net> Wed Aug 24 01:33:31 2016 +0300
tree 93ea9e4162da4c54ae5784d6643b7f6d55248d32
parent 5a5449d4eb46465e5d47fb20104e13122ea4110b

py/stream.c: use mp_obj_get_type in mp_get_stream_raise

In current state `mp_get_stream_raise` assumes that `self_in` is an object
and always performs a pointer derefence which may cause a segfault.

This function shall throw an exception whenever `self_in` does not implement
a stream protocol, that includes qstr's and numbers.

fixes #2331

py/stream.c

diff --git a/py/stream.c b/py/stream.c
index 473eb96..eef9080 100644
--- a/py/stream.c
+++ b/py/stream.c
@@ -94,8 +94,8 @@
 }
 
 const mp_stream_p_t *mp_get_stream_raise(mp_obj_t self_in, int flags) {
-    mp_obj_base_t *o = (mp_obj_base_t*)MP_OBJ_TO_PTR(self_in);
-    const mp_stream_p_t *stream_p = o->type->protocol;
+    mp_obj_type_t *type = mp_obj_get_type(self_in);
+    const mp_stream_p_t *stream_p = type->protocol;
     if (stream_p == NULL
         || ((flags & MP_STREAM_OP_READ) && stream_p->read == NULL)
         || ((flags & MP_STREAM_OP_WRITE) && stream_p->write == NULL)
@@ -167,7 +167,7 @@
                 // TODO what if we have read only half a non-ASCII char?
                 vstr_cut_tail_bytes(&vstr, more_bytes - out_sz);
                 if (out_sz == 0) {
-                    break; 
+                    break;
                 }
             }