From 0a7e6b9b84697ab0aa6109841cccc105aebd003a Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Tue, 23 Mar 2021 17:06:05 +0000
Subject: [PATCH] Subsystems: add checks to avoid crash on early exit
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Don’t crash if the user exits before subsystems are bound / init-ed
---
 simgear/structure/subsystem_mgr.cxx | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/simgear/structure/subsystem_mgr.cxx b/simgear/structure/subsystem_mgr.cxx
index 283a1365..f4863adf 100644
--- a/simgear/structure/subsystem_mgr.cxx
+++ b/simgear/structure/subsystem_mgr.cxx
@@ -340,6 +340,11 @@ SGSubsystemGroup::reinit ()
 void
 SGSubsystemGroup::shutdown ()
 {
+    if (_state < State::INIT) {
+        SG_LOG(SG_EVENT, SG_ALERT, "Shutdown of non-init-ed group:" << _name);
+        return;
+    }
+
     reverseForEach([this](SGSubsystem* s){
         this->notifyWillChange(s, State::SHUTDOWN);
         s->shutdown();
@@ -363,6 +368,11 @@ SGSubsystemGroup::bind ()
 void
 SGSubsystemGroup::unbind ()
 {
+    if (_state < State::BIND) {
+        SG_LOG(SG_EVENT, SG_ALERT, "Unbind of non-bound group:" << _name);
+        return;
+    }
+
     reverseForEach([this](SGSubsystem* s){
         this->notifyWillChange(s, State::UNBIND);
         s->unbind();