Running electron 1.2.0, which bundles v8 5.1.281.47 (node 6.2.0 bundles v8 5.0.71.47), i hit an issue where this code from leveldown (https://github.com/Level/leveldown/blob/master/src/database_async.cc#L141):

 v8::Local<v8::Value> argv[] = { Nan::Null() , returnValue }; callback->Call(2, argv);

calls the js callback with a boolean true as the first parameter.

Steps to reproduce:

create app.js with:

var db = require('level')('/tmp/db'); db.db.put('foo', 'bar', console.log.bind(console)); db.db.get('foo', err => console.log('err', err));

then

$ nvm use 6 $ npm install electron-prebuilt@1.2.0 level $ node_modules/.bin/electron app.js

It logs err true, although that argument should be null.

This error does not happen with electron 1.1.3, which is bundling v8 5.0.71.48.