Fix DirectPairing from crashing the editor and application if the script execution order calls SharingStage's OnDestroy first.

Robert Onulak · Robert Onulak · commit 5d9c6f07f1a8 · 2016-10-18T16:57:41.000-07:00
diff --git a/Assets/HoloToolkit/Sharing/Scripts/Utilities/DirectPairing.cs b/Assets/HoloToolkit/Sharing/Scripts/Utilities/DirectPairing.cs
@@ -63,7 +63,10 @@ void Start()
 
         void OnDestroy()
         {
-            if (this.sharingMgr != null)
+            // SharingStage's OnDestroy() might execute first in the script order. Therefore we should check if
+            // SharingStage.Instance still exists. Without the instance check, the execution of GetPairingManager
+            // on a disposed sharing manager will crash the Unity Editor and application.
+            if (SharingStage.Instance != null && this.sharingMgr != null)
             {
                 PairingManager pairingMgr = sharingMgr.GetPairingManager();
                 pairingMgr.CancelPairing();	// Safe to call, even if no pairing is in progress.  Will not cause a disconnect

Original file line number	Diff line number	Diff line change
`@@ -63,7 +63,10 @@ void Start()`
`63`	`63`
`64`	`64`	`void OnDestroy()`
`65`	`65`	`{`
`66`		`- if (this.sharingMgr != null)`
	`66`	`+ // SharingStage's OnDestroy() might execute first in the script order. Therefore we should check if`
	`67`	`+ // SharingStage.Instance still exists. Without the instance check, the execution of GetPairingManager`
	`68`	`+ // on a disposed sharing manager will crash the Unity Editor and application.`
	`69`	`+ if (SharingStage.Instance != null && this.sharingMgr != null)`
`67`	`70`	`{`
`68`	`71`	`PairingManager pairingMgr = sharingMgr.GetPairingManager();`
`69`	`72`	`pairingMgr.CancelPairing(); // Safe to call, even if no pairing is in progress. Will not cause a disconnect`