Support for Versions::ROOT_PACKAGE_NAME is broken

[stof]

Versions::getVersion(Versions::ROOT_PACKAGE_NAME) is expected to return the version of the root package.
But currently, the implementation forwards such call to Composer\InstalledVersions::getVersion() directly, which does not support the root package as package name. Info about the root package is exposed through Composer\InstalledVersions::getRootPackage()

[Ocramius]

I think Versions::ROOT_PACKAGE_NAME should be overall deprecated (#142, #139)

[stof]

sure. But in the meantime, it should still work. for now, there is no way to get the info about the root package anymore in this library.

[Ocramius]

Hmm, wait, so Composer\InstalledVersions::getVersion() has no root package info at all?

[stof]

Composer\InstalledVersions::getVersion() is only about packages installed in vendors (same than Composer\InstalledVersions::isInstalled().
The info about the root package are available through a separate Composer\InstalledVersions::getRootPackage() method.

[Ocramius]

I see, makes sense. Will indeed need some trickery to work :-\

[stof]

Well, I think this could look like this:

function getVersion(string $packageName)
{
    if ($packageName === self::ROOT_PACKAGE_NAME) {
        return \Composer\InstalledVersions::getRootPackage()['version']; // Or whatever is needed to output the right info
    }

    // existing code stays here
}

[Ocramius]

This seems to be only affecting the "fallback" version, when 'unknown/root-package@UNKNOWN' is used for a lookup. Not a massive fix though :-)