Improve handling of branch references

[stdout-se]

porcelain: fix listall_remote_branches symrefs and in_gitdir symlink path

• listall_remote_branches: handle symbolic refs (e.g. repo tool refs/remotes/m/master) and skip stale symrefs without raising
• in_gitdir: resolve paths so symlinked repo roots don't trigger ValueError (is_relative_to resolved vs unresolved)

Add tests in test_porcelain.py.

Resolves #91

[jorio]

Tjena! This looks like an interesting fix! I intend to take a closer look as soon as I get some time off. Sorry for the delay!

[jorio]

Thank you for the patch + tests, and thank you for your patience. Here are my notes:

How should we handle duplicates after resolving? For example, if m/master is symbolic and points to origin/master, then origin/master currently shows up twice (causing weirdness in the upstream context menu).

Ultimately, we're only showing direct refs in real remotes, so how about skipping all symbolic refs altogether, for now?

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Skip references without a branch name (e.g., refs/remotes/git-svn from git svn clone)

Skip references that don't match any known remote (e.g., stale refs from deleted remotes)

Could you please add tests to cover these code paths, so we don't inadvertently break this behavior in the future?

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Suggestion: the big 'for' loop could iterate over self.references.iterator() instead of self.listall_references(). This gets us real Reference objects instead of strings, and we can get rid of the additional lookup into self.references in the loop body.

[stdout-se]

Good feedback. I did an update and added some more tests. I guess the branches could be sorted as well, but maybe that's a job for the presentation layer and not listall_remote_branches?

[jorio]

but maybe that's a job for the presentation layer and not listall_remote_branches?

I agree, the upstream menu should probably honor the RefSort setting (Settings -> General -> Sort branches & tags). For now this only applies to the sidebar, but I should factor out SidebarModel.populateRefNodeTree so that the upstream menu can benefit from it, too.

Thank you for the PR!