issue34138: fix implementation of utf8 append

Author: gordonmessmer

Lib/imaplib.py

@@ -397,8 +397,6 @@ def append(self, mailbox, flags, date_time, message):
         else:
             date_time = None
         literal = MapCRLF.sub(CRLF, message)
-        if self.utf8_enabled:
-            literal = b'UTF8 (' + literal + b')'
         self.literal = literal
         return self._simple_command(name, mailbox, flags, date_time)
 
@@ -967,7 +965,11 @@ def _command(self, name, *args):
                 literator = literal
             else:
                 literator = None
-                data = data + bytes(' {%s}' % len(literal), self._encoding)
+                if self.utf8_enabled:
+                    data = data + bytes('UTF8 (~{%s}' % len(literal), self._encoding)
+                    literal = literal + b')'
+                else:
+                    data = data + bytes(' {%s}' % len(literal), self._encoding)
 
         if __debug__:
             if self.debug >= 4: