Description of problem:

When pushing to a container repository created outside of podman push, container_push_name_format will be set to nil. This causes an odd error message:

name invalid: Repository name 'foo' already exists in this product using a different naming scheme. Please retry your request with the format or destroy and recreate the repository using your preferred schema.

We should check for nil root_repo. container_push_name_format and return a nicer, clearer error message.

How reproducible:

Always

Is this issue a regression from an earlier version:

No

Steps to Reproduce:

1. Using podman, push to a container repository without a container_push_name_format (nil value).

Actual behavior:
See description above.

Expected behavior:
A clearer error message should be displayed.

Business Impact / Additional info:

N/A