unix-ffi/json: Fix json.loads() of a bytes object.

The conversion from bytes to string previosuly only if some other
argument was also given to `loads`.  This makes even a basic call with
no other arguments work.

Author: dhouck

unix-ffi/json/json/__init__.py

@@ -391,6 +391,8 @@ def loads(
     The ``encoding`` argument is ignored and deprecated.
 
     """
+    if isinstance(s, (bytes, bytearray)):
+        s = s.decode('utf-8')
     if (
         cls is None
         and object_hook is None
@@ -413,6 +415,4 @@ def loads(
         kw["parse_int"] = parse_int
     if parse_constant is not None:
         kw["parse_constant"] = parse_constant
-    if isinstance(s, (bytes, bytearray)):
-        s = s.decode('utf-8')
     return cls(**kw).decode(s)

unix-ffi/json/test_json.py

@@ -11,3 +11,9 @@
 
 # Doesn't work because JSON doesn't have tuples
 # assert inp == outp
+
+b = b'["foo", {"bar": ["baz", null, 1, 2]}]'
+outp2 = json.loads(b)
+
+assert b.decode('utf-8') == s
+assert outp == outp2