stream: Handle non-blocking errors in readline() properly.
Just like they handled in other read*(). Note that behavior of readline()
in case there's no data when it's called is underspecified in Python lib
spec, implemented to behave as read() - return None.
diff --git a/py/stream.c b/py/stream.c
index 862f3e6..ca474ba 100644
--- a/py/stream.c
+++ b/py/stream.c
@@ -293,9 +293,24 @@
mp_uint_t out_sz = o->type->stream_p->read(o, p, 1, &error);
if (out_sz == MP_STREAM_ERROR) {
+ if (is_nonblocking_error(error)) {
+ if (vstr->len == 1) {
+ // We just incremented it, but otherwise we read nothing
+ // and immediately got EAGAIN. This is case is not well
+ // specified in
+ // https://docs.python.org/3/library/io.html#io.IOBase.readline
+ // unlike similar case for read(). But we follow the latter's
+ // behavior - return None.
+ vstr_free(vstr);
+ return mp_const_none;
+ } else {
+ goto done;
+ }
+ }
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(error)));
}
if (out_sz == 0) {
+done:
// Back out previously added byte
// Consider, what's better - read a char and get OutOfMemory (so read
// char is lost), or allocate first as we do.