LavalinkNodeConnection's IsConnected still returns false after a successful reconnection

Created by: alexhorner

Summary

After a LavalinkNodeConnection has lost connection to its node, the IsConnected property remains false even if a successful reconnection has occured.

Details

Running on 4.0.0-rc2 packages across the board, .NET Core 3.1 on Windows 10 using Jetbrains Rider

Steps to reproduce

1. Establish a connection to a node and get the resulting LavalinkNodeConnection
2. Check IsConnected, it will be true
3. Kill LavaLink so that the connection is lost
4. Check IsConnected, it will be false
5. Start LavaLink and wait for it to accept the connection
6. Check IsConnected, it will be false when it should be true

Notes

I have looked at https://github.com/DSharpPlus/DSharpPlus/blob/7201d25c858e417097c297cec79477e9f334f8e2/DSharpPlus.Lavalink/LavalinkNodeConnection.cs and think I have identified the issue. Please could you triple check my findings?

(Looking in LavalinkNodeConnection.cs) It appears _isDisposed has an initial value of false as would be expected and is also set to false once again in the class constructor.

After a disconnect has occured, _isDisposed is set to true and StartAsync is called.

When a connection has been established once again by StartAsync, the value of _isDisposed is not updated to false therefore checking IsConnected returns false, even though a new connection has been established making the LavalinkNodeConnection usable again.