--- a/mercurial/utils/procutil.py Thu Jul 02 04:37:18 2020 +0200
+++ b/mercurial/utils/procutil.py Sat Jul 04 12:15:41 2020 +0200
@@ -67,6 +67,18 @@
io.BufferedIOBase.register(LineBufferedWrapper)
+def make_line_buffered(stream):
+ if pycompat.ispy3 and not isinstance(stream, io.BufferedIOBase):
+ # On Python 3, buffered streams can be expected to subclass
+ # BufferedIOBase. This is definitively the case for the streams
+ # initialized by the interpreter. For unbuffered streams, we don't need
+ # to emulate line buffering.
+ return stream
+ if isinstance(stream, LineBufferedWrapper):
+ return stream
+ return LineBufferedWrapper(stream)
+
+
# glibc determines buffering on first write to stdout - if we replace a TTY
# destined stdout with a pipe destined stdout (e.g. pager), we want line
# buffering (or unbuffered, on Windows)
@@ -77,10 +89,7 @@
elif pycompat.ispy3:
# On Python 3, buffered binary streams can't be set line-buffered.
# Therefore we have a wrapper that implements line buffering.
- if isinstance(stdout, io.BufferedIOBase) and not isinstance(
- stdout, LineBufferedWrapper
- ):
- stdout = LineBufferedWrapper(stdout)
+ stdout = make_line_buffered(stdout)
else:
stdout = os.fdopen(stdout.fileno(), 'wb', 1)