From ece526a99cf847d4132a896202c3a0234a537653 Mon Sep 17 00:00:00 2001
From: "alexey.lysiuk" <alexey.lysiuk@gmail.com>
Date: Tue, 23 Jun 2020 10:15:15 +0300
Subject: [PATCH] - fixed freeze with StartSlideshow called for undefined
 intermission

https://forum.zdoom.org/viewtopic.php?t=69079
---
 src/intermission/intermission.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/intermission/intermission.cpp b/src/intermission/intermission.cpp
index 29429177fa..ec8f7e394d 100644
--- a/src/intermission/intermission.cpp
+++ b/src/intermission/intermission.cpp
@@ -977,7 +977,11 @@ void F_StartIntermission(FIntermissionDescriptor *desc, bool deleteme, uint8_t s
 void F_StartIntermission(FName seq, uint8_t state)
 {
 	FIntermissionDescriptor **pdesc = IntermissionDescriptors.CheckKey(seq);
-	if (pdesc != NULL)
+	if (pdesc == nullptr)
+	{
+		gameaction = ga_nothing;
+	}
+	else
 	{
 		F_StartIntermission(*pdesc, false, state);
 	}