Allow to install/update only the composer.lock without installation

[mvorisek]

This is a feature request. For dependency analysises like this: https://gist.github.com/mvorisek/91ffee6254aed784daff3f1a0994d11a it is more than needed to be able to save the composer.lock file only without installing the actual files.

Of course it can be done from PHP, but this should be available via the composer CLI for easy use.

[Seldaek]

That'd be

composer/src/Composer/Installer.php

Lines 241 to 244 in 7e6fe58

	// TODO introduce option to set doInstall to false (update lock file without vendor install)
	$res = $this->doUpdate($localRepo, true);
	} else {
	$res = $this->doInstall($localRepo);

(on the 2.0 branch) if anyone wants to tackle it.