Cannot determine whether plugins are up to date or not

[gabrielwhite]

The new plugins UI allows users to automatically upgrade plugins that are hosted on wordpress.org.

For plugins that are not hosted on wordpress.org it's not possible to tell whether or not they are up to date.

There is no way for users to distinguish up to date (wordpress.org) plugins from out of date (non wordpress.org) plugins.

This is a security risk - users may think that all their plugins are up to date where in fact they are not.

There should be a small visual indication as to whether or not a plugin is up to date or whether it's not possible for wordpress to determine a plugins update status.

[lloydbudd]

Duplicate of #5117.