py3: introduce a wrapper for __builtins__.{raw_,}input() In order to make this work, we have to wrap the io streams in a TextIOWrapper so that __builtins__.input() can do unicode IO on Python 3. We can't just restore the original (unicode) sys.std* because we might be running a cmdserver, and if we blindly restore sys.* to the original values then we end up breaking the cmdserver. Sadly, TextIOWrapper tries to close the underlying stream during its __del__, so we have to make a sublcass to prevent that. If you see errors like: TypeError: a bytes-like object is required, not 'str' On an input() or print() call on Python 3, the substitution of sys.std* is probably the root cause. A previous version of this change tried to put the bytesinput() method in pycompat - it turns out we need to do some encoding handling, so we have to be in a higher layer that's allowed to use mercurial.encoding.encoding. As a result, this is in util for now, with the TextIOWrapper subclass hiding in encoding.py. I'm not sure of a better place for the time being. Differential Revision: https://phab.mercurial-scm.org/D299

--- a/mercurial/util.py	Wed Jul 26 23:33:26 2017 -0400
+++ b/mercurial/util.py	Mon Jul 24 14:38:40 2017 -0400
@@ -172,6 +172,18 @@
 def safehasattr(thing, attr):
     return getattr(thing, attr, _notset) is not _notset
 
+def bytesinput(fin, fout, *args, **kwargs):
+    sin, sout = sys.stdin, sys.stdout
+    try:
+        if pycompat.ispy3:
+            sys.stdin, sys.stdout = encoding.strio(fin), encoding.strio(fout)
+            return encoding.strtolocal(input(*args, **kwargs))
+        else:
+            sys.stdin, sys.stdout = fin, fout
+            return raw_input(*args, **kwargs)
+    finally:
+        sys.stdin, sys.stdout = sin, sout
+
 def bitsfrom(container):
     bits = 0
     for bit in container: