./scripts/feeds update may fail with: "fatal: refusing to merge unrelated histories"

[Rafał Miłecki]

I've a custom feeds git repository with development branch that gets rebased.

I use it with a simple feeds.conf "src-git" entry like:
src-git foo git at example.foo:my-packages.git;feature

The problem is that ./scripts/feeds uses a simple "git pull --ff-only"
for updates. That doesn't work for branches that get rebased. It
results in:
fatal: refusing to merge unrelated histories

Could some git expert suggest a fix for that? I'd like to modify
"update" command of "src-git" to support rebases.
For full clones we could probably use "git fetch" and "git rebase" but
I don't know the proper solution for clones with "--depth 1".

-- 
Rafał