py3: fix slicing of byte string in revlog.compress()
I tried .startswith('\0'), but data wasn't always a bytes nor a bytearray.
--- a/mercurial/revlog.py Sun Mar 26 16:31:01 2017 +0900
+++ b/mercurial/revlog.py Sun Mar 26 17:12:06 2017 +0900
@@ -1488,7 +1488,7 @@
# The revlog compressor added the header in the returned data.
return '', compressed
- if data[0] == '\0':
+ if data[0:1] == '\0':
return '', data
return 'u', data