Fix document.write with async script

src/write-stream.js

@@ -454,6 +454,11 @@ export default class WriteStream {
   _onScriptDone(tok) {
     // Pop script and check nesting.
     if (tok !== this.scriptStack[0]) {
+      if (this.deferredRemote === tok) {
+        // probably using document.write to output an async script with releaseAsync set to true
+        this.deferredRemote = null;
+        return;
+      }
       this.options.error({msg: 'Bad script nesting or script finished twice'});
       return;
     }

test/unit/tokenprocessing.spec.js

@@ -113,5 +113,20 @@ describe('tokenprocessing', () => {
     );
   });
 
-});
+  it('does something wierd.', done => {
+    const div = document.createElement('div');
+    div.id = 'document-write-async';
+    document.body.appendChild(div);
+    postscribe(div, '<script>document.write("<scr"+"ipt async src=\'remote/describe-write.js\'></scr"+"ipt>");</script>', {
+      releaseAsync: true,
+      done: () => {
+        expect(div.innerHTML).to.contain('<script async="" src="remote/describe-write.js"></script>');
+        done();
+      },
+      error: (error) => {
+        done(error);
+      }
+    });
+  });
 
+});