RFR: 1304: The 'git skara sync' command often fails

[Erik Joelsson]

On Tue, 11 Jan 2022 21:12:42 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

> This is a partial rework of the rather recent change to "git skara fork" and "git skara sync". That patch tried to protect the user from syncing changes to the wrong host unintentionally, but unfortunately, it turned out to make it a bit too hard.
> 
> With this patch I'm fixing some outright bugs as well as dialing back the protection a little bit. First the clear bugfixes:
> 
> 1. When trying to figure out the official fork parent from the origin, setup and use credentials properly.
> 2. When forking and cloning a repository into a sub directory of an existing local repository, do not set the forge.name config in the existing local repository.
> 
> Behavioral changes:
> 
> 1. Do not require --force when explicitly setting --to and/or --from. I believe that if you set those parameters, you are already explicit enough.
> 2. Do require --force whenever the derived to and from do not share the same hostname. This should better catch the sensitive situation when changes are likely to be going the wrong way.
> 3. Since looking up the fork parent from the origin forge is unreliable, only use it when possible and mostly for verification, and only use it as the last option for default from repo.
> 
> So to summarize, here is the expected behavior for choosing the repository from which to sync changes from (this now matches the existing documentation at https://wiki.openjdk.java.net/display/SKARA/git-sync).
> 
> 1. The --from option if set either on the command line or configuration
> 2. A remote named "upstream"
> 3. The fork parent from the origin forge

I think when it works, it does provide a good extra sanity check. I've also fixed some of the cases where it didn't work (when the 'fork' command misconfigured the repository with forge.name for example), so with a correctly configured proxy, it's not noticeably slow now. The only case left that I know about is my own, when you don't have a general proxy config in the shell, but instead use the git config "http.<githuburl\>.proxy=<proxyhost\>". This git config is recommended in internal Skara documentation, but not picked up by Skara itself. I hope to fix this in a later enhancement.

For other cases where we know that it won't work, or isn't needed, we just skip it. That would be when the remote is ssh based, or --force is set.

This made me realize that there is a corner case where this patch doesn't work well. If the user has no upstream and runs with just '--force' on the command line, then 'sync' will not find any from repo at all. I could fix this.

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PR: https://git.openjdk.java.net/skara/pull/1273