Always flush output before reading line for simplicity

lib/nntp/tiny/session.py

@@ -48,15 +48,16 @@ class Session():
         self.perms:      Optional[UserPermission] = None
         self.article_id: Optional[int]            = None
 
-    def readline(self):
-        return self.buf.readline(self.sock)
-
     def print(self, text: str, end: str="\r\n"):
         return self.output.print(text, end)
 
     def flush(self):
         return self.output.flush()
 
+    def readline(self):
+        self.flush()
+        return self.buf.readline(self.sock)
+
     def end(self):
         return self.print('.')
 
@@ -800,7 +801,6 @@ class Session():
 
     def greet(self):
         self.respond(ResponseCode.NNTP_SERVICE_READY_POST_PROHIBITED)
-        self.flush()
 
     def handle_command(self):
         line = self.readline()
@@ -832,7 +832,6 @@ class Session():
         try:
             while self.active:
                 self.handle_command()
-                self.flush()
 
             self.sock.close()
         except BrokenPipeError: