Fix for empty namespaces. #13459

[johncook]

Fixes #13459

Changes proposed in this Pull Request:

If the namespace is an empty string then NULL is passed into ClassMapGenerator::createMap().

Testing instructions:

Create a composer.json file with the following content:

{
    "description": "Tests automattic/jetpack-autoloader",
    "keywords": [
        "automatic jetpack autoloader"
    ],
    "repositories": [
        {
            "type": "path",
            "url": "/path/to/your/jetpack/packages/autoloader",
            "options": {
                "symlink": true
            }
        }
    ],
    "require": {
        "automattic/jetpack-autoloader": "@dev",
        "wp-cli/wp-cli": "^1.0"
    }
}

Then run composer install.

Once you see the bug, rm -rf vendor composer.lock, apply the patch above, and then run composer install again. The error should disappear.

Proposed changelog entry for your changes:

• General: avoid conflicts when using Jetpack alongside other plugins or services that rely on an Autoloader.

[jetpackbot]

Thank you for the great PR description!

When this PR is ready for review, please apply the [Status] Needs Review label. If you are an a11n, please have someone from your team review the code if possible. The Jetpack team will also review this PR and merge it to be included in the next Jetpack release.

Scheduled Jetpack release: October 1, 2019.
Scheduled code freeze: September 24, 2019

Generated by 🚫 dangerJS against 67d2177

[jeherve]

Could you provide testing instructions so we can try to reproduce the issue and check that the patch fixes the problem?

Thank you!

[johncook]

@jeherve

The easiest way to test is to create a composer.json file with the following content:

{
  "description": "Tests automattic/jetpack-autoloader",
  "keywords": ["automatic jetpack autoloader"],
  "repositories": [
    {
      "type": "composer",
      "url": "https://wpackagist.org"
    }
  ],
  "require": {
    "automattic/jetpack-autoloader": "^1.2",
    "wp-cli/wp-cli": "^1.0"
  }
}

Then running composer install or composer update.

[jeherve]

This works well in my tests.

[gravityrail]

LGTM