From cf85a6470fb17e1038f7448b9ed623ed83a424b5 Mon Sep 17 00:00:00 2001
From: Jakub Kuczys <6032823+jack1142@users.noreply.github.com>
Date: Sun, 5 Jun 2022 02:46:17 +0200
Subject: [PATCH] Wait for two 'Started Launcher' lines before connecting to
 managed LL (#5751)

---
 redbot/cogs/audio/manager.py | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/redbot/cogs/audio/manager.py b/redbot/cogs/audio/manager.py
index a46e8221a..6def104be 100644
--- a/redbot/cogs/audio/manager.py
+++ b/redbot/cogs/audio/manager.py
@@ -313,12 +313,22 @@ class ServerManager:
 
     async def _wait_for_launcher(self) -> None:
         log.info("Waiting for Managed Lavalink node to be ready")
+        # Since Lavalink jar 3.4.0_1346, there are two "Started Launcher" lines logged
+        # before Lavalink is ready to receive requests.
+        started_line_seen = False
         for i in itertools.cycle(range(50)):
             line = await self._proc.stdout.readline()
             if _RE_READY_LINE.search(line):
-                self.ready.set()
-                log.info("Managed Lavalink node is ready to receive requests.")
-                break
+                if started_line_seen:
+                    self.ready.set()
+                    log.info("Managed Lavalink node is ready to receive requests.")
+                    break
+                else:
+                    log.debug(
+                        "Seen first 'Started Launcher' line from Managed Lavalink node."
+                        " Waiting for the second one..."
+                    )
+                    started_line_seen = True
             if _FAILED_TO_START.search(line):
                 raise ManagedLavalinkStartFailure(
                     f"Lavalink failed to start: {line.decode().strip()}"