@@ -84,3 +84,35 @@ def __eq__(self, other):
         for var, value in copy_context().items()
         if var.name == "child_marker"
     ] == []
+
+
+def context_cache_does_not_outlive_its_context():
+    import contextvars
+
+    for factory_name in ("new", "copy"):
+        for _ in range(100):
+            var = contextvars.ContextVar("var", default="default")
+            empty = contextvars.Context()
+            ctx = contextvars.Context() if factory_name == "new" else empty.copy()
+            ctx.run(var.set, "cached")
+            del ctx
+            ctx = contextvars.Context() if factory_name == "new" else empty.copy()
+            assert list(ctx.items()) == []
+            assert ctx.run(var.get) == "default"
+            assert ctx.run(var.get, "explicit default") == "explicit default"
+
+            missing = contextvars.ContextVar("missing")
+            ctx.run(missing.set, "cached")
+            del ctx
+            ctx = contextvars.Context() if factory_name == "new" else empty.copy()
+            try:
+                ctx.run(missing.get)
+            except LookupError:
+                pass
+            else:
+                raise AssertionError(
+                    "an empty context returned a destroyed context value"
+                )
+
+
+context_cache_does_not_outlive_its_context()