Resource defaults and resource overrides can lead to incorrect parameter conflicts

The error message is:

Error: Parameter 'require' is already set on Package[pip] by #<Puppet::Resource::Type:0x005570c96bc260> at /home/branan/.puppetlabs/etc/code/environments/production/modules/foo/manifests/init.pp:4; cannot redefine at /home/branan/.puppetlabs/etc/code/environments/production/site.pp:1 on node rycon.delivery.puppetlabs.net

This was discovered while Ops was trying to upgrade to a pre-release hoyt build.

See the attached tarball for a minimal reproduction. This is an environment that can be untarred into a code dir and verified with puppet apply --debug --noop $CODEDIR/environments/repro/site.pp. The error only occurs when the resource override is in place. If the overridden parameters are inlined into the resource declaration, it works as expected.

This was apparently introduced as part of PUP-7484, and is in general related to the PUP-25 work.

According to a bisect, the breaking commit is 38413cd78c61fe34d2ee343ef773a07b4786f65a