Bug#828775: Support multiple patch queues branches

[Michael Biebl]

Package: git-buildpackage
Version: 0.7.5
Severity: wishlist

Hi Guido,

as discussed offline, in pkg-systemd we typically have two type of
patches: upstream cherrry-picks and Debian specific patches. Upstream
cherry-picks happen much more often and should ideally be applied
directly on upstream master (to avoid merge conflicts), i.e. before the
Debian patches.

With the current gbp pq approach, the workflow atm looks like:
gbp pq import --force
git cherry-pick <commitid>
  which means the new cherry-pick is the last patch in
  debian/patches/series
git rebase -i
  to reorder the new cherry-picked patch

Ideally we would have two patch queue branches: one for upstream
cherry-picks and one for Debian specific patches.

Cherry-picking an upstream commit would then be as simple as switching
to the upstream pq branch, running git cherry-pick and exporting the
complete patch series via gbp pq export.
Combining the patches from two different branches could obviously lead
to merge conflicts on export, so we maybe would need something like a
gbp pq rebase <second patch queue>.

A bonus would be, if this is combined with topics, i.e. for each topic
"gbp import" would create separate branches.

I hope you get the idea. 

Regards,
Michael


-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.6.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages git-buildpackage depends on:
ii  devscripts            2.16.5
ii  git                   1:2.8.1-1
ii  man-db                2.7.5-1
ii  python-dateutil       2.4.2-1
ii  python-pkg-resources  20.10.1-1.1
ii  python-six            1.10.0-3
pn  python:any            <none>

Versions of packages git-buildpackage recommends:
ii  cowbuilder       0.80
ii  pbuilder         0.225.1
ii  pristine-tar     1.34
ii  python-requests  2.10.0-2

Versions of packages git-buildpackage suggests:
ii  python-notify  0.1.1-4
ii  sudo           1.8.15-1.1
ii  unzip          6.0-20

-- no debconf information