[Tarantool-patches] [PATCH] tools: add a script that checks submodules' commits

[Alexander Turenko]

Nice idea :)

I don't mind any scripts that ease developer / maintainer life.

The patch is okay for push (from my point of view), however I would
share some thoughts around. Feel free to pass them over if you don't
want to pay more time here.

I would extend the script for all long-term branches (1.10, 2.*, master)
with a submodule specific rules:

1. test-run's commit should be reachable from test-run's master for all
   long-term branches.
2. I guess it is the same for small, but from what I heard, we possibly
   will fork a stable branch. So the rule will be like (not sure about X
   value):
   - if tarantool's branch is 1.10 / 2.X (X < 8) => small's commit should
     be reachable from small's tarantool-1.10 branch.
   - 2.X (X >= 8), master => reachable from small's master.
3. There is master and tarantool-1.10 in msgpuck, similar to above.

I would also explicitly skip the checks for pushing to any other branch.
So the script may be called before any push and may be integrated into
`.git/hooks/pre-push`. This means, a maintainer will place it here once
and will not need to run it manually.

Maybe it worth to look at the `.git/hooks/pre-push` format from
beginning. At least it accepts a branch to push as the second parameter
that may be useful.

Anyway, the script is useful without those enhancements.

WBR, Alexander Turenko.

> When the fix is merged to mater it's very simple to make a mistake:

Just if'll spin around again: mater -> master.