Make cleanup more robust

Signed-off-by: Rahix <rahix@rahix.de>

bc.lua

@@ -116,9 +116,20 @@ function BaseControl:new(network)
   }
   setmetatable(self, {__index=BaseControl, __call=BaseControl.new})
 
+  -- Create a weak reference to self.  This allows us to uninstall the
+  -- network handler automatically once this instance gets garbage-collected.
+  do
+    local weak = setmetatable({self=self}, {__mode="v"})
+    local network = self.network
+
     self.network:start(function(remote, msg)
-    self:_network_handler(remote, msg)
+      if weak.self ~= nil then
+        weak.self:_network_handler(remote, msg)
+      else
+        network:stop()
+      end
     end)
+  end
   self.network:broadcast{ty=Message.Hello}
 
   return self

network.lua

@@ -21,6 +21,10 @@ function network.deregister(addr)
   nodes[addr] = nil
 end
 
+function network.get_callback(addr)
+  return nodes[addr]
+end
+
 function network.send(addr, port, msg)
   local callback = nodes[addr]
   if callback == nil then

tests/cleanup.lua

@@ -11,11 +11,14 @@ function test_clean_simple()
   bc:close()
 
   local bc = BaseControl:finalize()
+  assert_true(network.get_callback(addr) ~= nil, "callback not registered")
   bc:close()
 
   assert_error(function()
     bc:nouns()
   end)
+
+  assert_nil(network.get_callback(addr), "callback still in network")
 end
 
 function test_clean_network()
@@ -66,3 +69,25 @@ function test_clean_network2()
     bc2:get("cln3")
   end)
 end
+
+function test_unclean_deregister()
+  local bc = BaseControl:new()
+  local addr = network.get_scene()
+
+  network.set_scene("UNCL-DEREG")
+  network.send(
+    addr,
+    BaseControl.Network.default_port,
+    serialization.serialize{ty=BaseControl.Message.Hello}
+  )
+
+  assert_true(network.get_callback(addr) ~= nil, "callback not registered")
+  bc = nil
+  collectgarbage()
+  network.send(
+    addr,
+    BaseControl.Network.default_port,
+    serialization.serialize{ty=BaseControl.Message.Hello}
+  )
+  assert_nil(network.get_callback(addr), "callback still in network")
+end