From 91a6ff1d81bd3626d356f114b061e142aa3b2af7 Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Tue, 11 May 2021 11:30:41 +0200
Subject: [PATCH] task: Prevent "unexpected task state" when cancelling task
 sometimes

---
 panda/src/event/asyncFuture.cxx | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/panda/src/event/asyncFuture.cxx b/panda/src/event/asyncFuture.cxx
index 6828213942..b1c8ce0fc3 100644
--- a/panda/src/event/asyncFuture.cxx
+++ b/panda/src/event/asyncFuture.cxx
@@ -315,6 +315,11 @@ wake_task(AsyncTask *task) {
     task->_state = AsyncTask::S_servicing;
     return;
 
+  case AsyncTask::S_active:
+    // It could have already been activated, such as by a cancel() which then
+    // indirectly caused the awaiting future to be cancelled.  Do nothing.
+    return;
+
   case AsyncTask::S_inactive:
     // Schedule it immediately.
     nassertv(task->_manager == nullptr);