Correctly resolve promises when package type changes

[aschempp]

This fixes #10069

When the type of a package changes, Composer does an uninstall and install instead of an update. 78d7792 added support for handling promises of the installer, but because it returns the uninstall promise instead of the resulting install promise, the cleanup operation in https://github.com/composer/composer/blob/master/src/Composer/Installer/InstallationManager.php#L420 runs before install is executed.

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FYI instead of setting $promise = $promise->then(…) we could also just return $promise->then(…)

[cmodijk]

I just tried the fix @aschempp supplied and this indeed solved the problem #10069

[Seldaek]

Thanks!

[jnaklaas]

Can I test this, I've got the same bug when extracting my latest private packages? Tried to composer self-update master but that didn't work.

[Toflar]

You can update to the snapchot channel using composer selfupdate --snapshot.

[jnaklaas]

Okay thanks. Tried that, the issue didn't get resolved though. I also noticed it's not exactly the same bug.