joining thread

when joining a thread and entering it's own thread number the thread disappears
 
there should be a check on it with a message that a thread can't be joined to itself.

next is more difficult to explain
 
this is what i did
 
I have 3 threads
#1 subject test 1
#2 subject test 2
#3 subject test 3
 
then I joined 3 with two
 
so i have
#1 subject test 1
#2 subject test 2 and reply from #3
 
then I joined #2 with #1
 
so I have thread #1 with subject 1 with to replies from #2 & #3
so far so good
i split of #3
so I have #1 with reply from #2
and new thread from reply which was #3
 
then I split of #2 from #1
and there it went wrong
#2 wasn't split off but #1 got the subject of #2

 
I hope you can follow what happened Sam