Use package location if one is specified

[tgriesser]

I ran into an issue when trying to use the package config to build a project, where the config is:

({
    baseUrl: ".",
    optimize: 'none',
    cjsTranslate: true,
    paths: {
      lodash: './node_modules/lodash/lodash'
    },
    packages: [{
      name: 'bluebird',
      location: 'node_modules/bluebird',
      main: './js/main/bluebird.js'
    }],
    name: "knex",
    out: "knex-built.js"
})

I was getting the error:

Tracing dependencies for: knex
Error: ENOENT, no such file or directory '/Users/tgriesser/Github/knex/bluebird/js/main/global.js'
In module tree:
    knex
      lib/raw
        lib/common
          lib/promise
            bluebird/js/main/promise

In this case, it was resolving relative package paths relative to the main file, which wasn't using the location to find the correct path. So it was doing:

/Users/tgriesser/Github/knex/bluebird/js/main/global.js

rather than

/Users/tgriesser/Github/knex/node_modules/bluebird/js/main/global.js

This pull request adds a check to see if a location is defined and if so replaces appropriately in the package name.

[jrburke]

Thanks for pointing this out. The fix was a bit more involved, and depended on another fix that is landing for 2.1.10, so I could not use this pull request directly. However, it should be fixed for 2.1.10.

[jrburke]

Turns out there was a larger issue with compatibility with node ID resolution: they treat 'example.js' and 'example' as the same module ID. So instead of the packages-specific fix, there is a new nodeIdCompat config value that if set to true, will treat those IDs as the same. So be sure to set that if using modules installed from npm once 2.1.10 is released.