src: make cross-context MakeCallback() calls work

Check that invoking a callback on a receiver from a different context
works.

It ran afoul of an `env->context() == isolate->GetCurrentContext()`
assertion so retrieve the environment from the callback context and
the context to enter from the environment's context() method.

We could also have retrieved the environment from the receiver's context
and that would have made little practical difference.  It just seemed
more correct to get it from the callback context because that is the
actual execution context.

PR-URL: https://github.com/nodejs/node/pull/9221
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/test/addons/make-callback/test.js b/test/addons/make-callback/test.js
index 43ad014c4a..b67d1146a6 100644
--- a/test/addons/make-callback/test.js
+++ b/test/addons/make-callback/test.js
@@ -36,6 +36,10 @@ const recv = {
 assert.strictEqual(42, makeCallback(recv, 'one'));
 assert.strictEqual(42, makeCallback(recv, 'two', 1337));
 
+// Check that callbacks on a receiver from a different context works.
+const foreignObject = vm.runInNewContext('({ fortytwo() { return 42; } })');
+assert.strictEqual(42, makeCallback(foreignObject, 'fortytwo'));
+
 // Check that the callback is made in the context of the receiver.
 const target = vm.runInNewContext(`
     (function($Object) {