From 654c72fb7e19c6ee6f5d46249220b5257c5bea9e Mon Sep 17 00:00:00 2001
From: humbletim <humbletim@gmail.com>
Date: Mon, 27 Feb 2017 22:58:59 -0500
Subject: [PATCH] Add weakRef guard to detect ScriptEngine deletion during
 ScriptCache::getScriptContents

---
 libraries/script-engine/src/ScriptEngine.cpp | 8 +++++++-
 libraries/script-engine/src/ScriptEngine.h   | 2 +-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/libraries/script-engine/src/ScriptEngine.cpp b/libraries/script-engine/src/ScriptEngine.cpp
index d4b6d592c0..bbe2d90ba4 100644
--- a/libraries/script-engine/src/ScriptEngine.cpp
+++ b/libraries/script-engine/src/ScriptEngine.cpp
@@ -1620,8 +1620,14 @@ void ScriptEngine::loadEntityScript(const EntityItemID& entityID, const QString&
     setEntityScriptDetails(entityID, newDetails);
 
     auto scriptCache = DependencyManager::get<ScriptCache>();
+    // note: see EntityTreeRenderer.cpp for shared pointer lifecycle management
+    QWeakPointer<ScriptEngine> weakRef(sharedFromThis());
     scriptCache->getScriptContents(entityScript,
-        [this, entityScript, entityID](const QString& url, const QString& contents, bool isURL, bool success, const QString& status) {
+        [this, weakRef, entityScript, entityID](const QString& url, const QString& contents, bool isURL, bool success, const QString& status) {
+            if (!weakRef) {
+                qCWarning(scriptengine) << "loadEntityScript.contentAvailable -- ScriptEngine was deleted during getScriptContents!!";
+                return;
+            }
             if (isStopping()) {
 #ifdef DEBUG_ENTITY_STATES
                 qCDebug(scriptengine) << "loadEntityScript.contentAvailable -- stopping";
diff --git a/libraries/script-engine/src/ScriptEngine.h b/libraries/script-engine/src/ScriptEngine.h
index 7f533d2f40..b988ccfe90 100644
--- a/libraries/script-engine/src/ScriptEngine.h
+++ b/libraries/script-engine/src/ScriptEngine.h
@@ -78,7 +78,7 @@ public:
     QUrl definingSandboxURL { QUrl("about:EntityScript") };
 };
 
-class ScriptEngine : public BaseScriptEngine, public EntitiesScriptEngineProvider {
+class ScriptEngine : public BaseScriptEngine, public EntitiesScriptEngineProvider, public QEnableSharedFromThis<ScriptEngine> {
     Q_OBJECT
     Q_PROPERTY(QString context READ getContext)
 public: