The log manager had a single external-callback slot, but the WebSocket
debugger registers one per *connection* - LogBroadcaster is a local in the
per-connection handler. So with two clients attached (the bundled JS debugger
in a browser and Tools/wsdbg, say) the second one to connect silently took the
log stream away from the first, and then whichever disconnected first cleared
the slot and stopped delivery to the other as well. A one-shot wsdbg command is
enough to do it: connect, take the stream, exit, and the long-lived listener
that was watching the log goes quiet with nothing to say why.
Make it a list with add/remove by handle. The dispatch loop holds the lock
across the callbacks so a listener can't be freed while one is running - which
is what lets LogBroadcaster delete its listener straight after removing it.
Enabling and disabling LogOutput::ExternalCallback belongs to the list now, and
disabling only happens when the last callback goes away.
libretro registers one of these too, and never removes it; it just moves to the
new call. It can't actually collide with the debugger - the libretro build
doesn't compile Core/Debugger/WebSocket at all - but there's no reason for it
to keep using an API that only has room for one caller.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
