From the man page of pthread_join;

NOTES top

   After a successful call to pthread_join(), the caller is
   guaranteed that the target thread has terminated.  The caller may
   then choose to do any clean-up that is required after termination
   of the thread (e.g., freeing memory or other resources that were
   allocated to the target thread).

   Joining with a thread that has previously been joined results in
   undefined behavior.

   **Failure to join** with a thread that is joinable (i.e., one that is
   not detached), produces a "zombie thread".  Avoid doing this,
   since each zombie thread consumes some system resources, and when
   enough zombie threads have accumulated, it will no longer be
   possible to create new threads (or processes).

Hi, thanks for the PR and sorry for the delay! 🙇

I think I understood the basic problem and what this PR fixes, I just have a few questions, marked in the PR's code.

So just to give some background.

I was working on a system, using libsvnserver in the threaded variation, and I was loosing memory (memory leak). So I started testing and noticed with htop on the server that, each time the client disconnects, I was loosing memory. So I focussed on libsvnserver and after a long time testing found that the memory leak didn't happen when I was using libsvnserver without threading.

So I focussed on threading, disabling code to find where the leak was. And in the end found the leak happened at thread ending. At that time I noticed that the leak happened at the end of the thread. So I investigated the thread and found that it wasn't joined at the end. Only when the server is stopped the, at that time, still running thread was joined.

At this point I knew what the problem was but I couldn't find a good place to join the client thread. So I decided it would be easier to detach the thread as a detached thread frees it's own memory (no join needed).