Pushing by image ID is not allowed in the Docker CLI and not supported by the registry. An unnamed image also cannot be pushed to a private registry, since no endpoint is specified and it will default to the hub. The hub also does not support this use case, therefore removing the code path is the best solution.
The ability to push a layer without a name is unsupported by the v2 registry.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Upstream-commit: db2d875b5e621378baf690d261969712fbfffcfd
Component: engine