don't throw on null stack

Scott Williams · Scott Williams · commit 58edeadec857 · 2019-08-23T09:11:45.000+01:00
diff --git a/src/Tocsoft.DateTimeAbstractions/Clock.cs b/src/Tocsoft.DateTimeAbstractions/Clock.cs
@@ -70,7 +70,7 @@ internal static IDisposable Pin(DateTimeProvider provider)
 
         private static void Pop()
         {
-            clockStack.Value = clockStack.Value.Pop();
+            clockStack.Value = clockStack.Value?.Pop();
         }
 
         private sealed class PopWhenDisposed : IDisposable

Original file line number	Diff line number	Diff line change
`@@ -70,7 +70,7 @@ internal static IDisposable Pin(DateTimeProvider provider)`
`70`	`70`
`71`	`71`	`private static void Pop()`
`72`	`72`	`{`
`73`		`- clockStack.Value = clockStack.Value.Pop();`
	`73`	`+ clockStack.Value = clockStack.Value?.Pop();`
`74`	`74`	`}`
`75`	`75`
`76`	`76`	`private sealed class PopWhenDisposed : IDisposable`