glib: Don't double-panic if ThreadGuard::into_inner is called on the wrong thread.

Author: zachs18

glib/src/thread_guard.rs

@@ -87,14 +87,14 @@ impl<T> ThreadGuard<T> {
     /// created.
     #[inline]
     pub fn into_inner(self) -> T {
+        // We wrap `self` in `ManuallyDrop` to defuse `ThreadGuard`'s `Drop` impl.
+        let mut this = ManuallyDrop::new(self);
+
         assert!(
-            self.thread_id == thread_id(),
+            this.thread_id == thread_id(),
             "Value accessed from different thread than where it was created"
         );
 
-        // We wrap `self` in `ManuallyDrop` to defuse `ThreadGuard`'s `Drop` impl.
-        let mut this = ManuallyDrop::new(self);
-
         // SAFETY: We are on the right thread, and this.value will not be touched after this
         unsafe { ManuallyDrop::take(&mut this.value) }
     }