(part of)
commit 0019b6e68af9bda8b368a7073e5eb927607f00e2
Author: Sławomir Nizio <slawomir.nizio@sabayon.org>
Date:   Sat Mar 21 22:08:50 2020 +0100

    [entropy.misc, rigo] fix file-like objects with Python 3
    
    FakeOutFile and LogFile need .buffer like Python 3 "text" file objects
    which is needed when in rigo standard output/error is replaced, and then
    it reaches Portage which does this:
    
                if sys.hexversion >= 0x3000000 and fd in (sys.stdout, sys.stderr):
                        fd = fd.buffer
        fd.write(mystr)
    
    (/usr/lib64/python3.6/site-packages/portage/util/__init__.py).
    
    Entropy internal code did not need this.
    
    Note, after this commit, changes done previously:
        1)
        commit 0869912ec4c630d2946e835b2585367e233c1c15
    
            [entropy.spm] Rigo related Python 3 fix
    
              File "/usr/lib64/python3.6/site-packages/entropy/spm/plugins/interfaces/portage_plugin/__init__.py", line 101, in _pusher
                self._std.buffer.write(chunk)
            AttributeError: 'FakeOutFile' object has no attribute 'buffer'
    
        2)
        commit 8700aade27cb4117bf102afc7bd22ba6acfd8aa8
    
            [entropy.spm, rigo] Rigo related Python 3 fixes
    
            1)
              File "/usr/lib/python-exec/python3.6/RigoDaemon_app.py", line 362, in _pusher
                fobj.write(chunk)
            TypeError: write() argument must be str, not bytes
    
            2)
              File "/usr/lib64/python3.6/site-packages/entropy/spm/plugins/interfaces/portage_plugin/__init__.py", line 77, in __init__
                self.buffer = Writer(self, self._std.buffer)
            AttributeError: 'FakeOutFile' object has no attribute 'buffer'
    
        (...)
    
    could be likely reverted; not tested, it could be better to have them anyway to
    avoid futher re/encoding/checks if conversions are needed (subjective).
    
    Fixes bug 5899.

diff --git lib/entropy/misc.py lib/entropy/misc.py
index bb4a94af8..d216bd693 100644
--- lib/entropy/misc.py
+++ lib/entropy/misc.py
@@ -35,7 +35,8 @@ import threading
 from collections import deque
 
 from entropy.const import etpConst, const_isunicode, \
-    const_isfileobj, const_convert_log_level, const_setup_file
+    const_isfileobj, const_convert_log_level, const_setup_file, \
+    const_convert_to_unicode
 from entropy.exceptions import EntropyException
 
 import entropy.tools
@@ -1665,6 +1666,24 @@ class FastRSS(object):
         const_setup_file(self.__file, etpConst['entropygid'], 0o664)
 
 
+class FileobjCompatBuffer:
+
+    """
+    Compatibility shim for file object with the buffer attribute.
+    To be used with classes whose write method expect strings.
+    """
+
+    def __init__(self, parent):
+        self._parent = parent
+
+    def write(self, msg):
+        msg_str = const_convert_to_unicode(msg)
+        self._parent.write(msg_str)
+
+    def flush(self):
+        self._parent.flush()
+
+
 class LogFile:
 
     """ Entropy simple logging interface, works as file object """
@@ -1715,6 +1734,9 @@ class LogFile:
             LogFile.DATE_FORMAT))
         self.__logger.addHandler(self.__handler)
 
+        if const_is_python3():
+            self.buffer = FileobjCompatBuffer(self)
+
     def __enter__(self):
         """
         Just return self, configuration is done in __init__