The instructions at:
http://www.denx.de/wiki/U-Boot/CustodianGitTrees
... indicate that downstream branches should be rebased onto ${upstream}/master immediately prior to sending a pull request. I'm not sure this is correct any more, given that upstream master branches now pull in downstream branches via "git merge" rather than "git rebase". Should that page be changed?
The question then becomes: What commit should downstream branches use as their baseline. I assert that they should be free to choose any commit in their upstream master branch (or merge in any upstream commit), or any further upstream branch all the way up to u-boot/master.
As background, I want to send a commit to the Tegra tree that enables use of CONFIG_CMD_FS_GENERIC, and additionally, re-write bootcmd in Tegra's default environment to use the new shell commands that config option enables.
However, the commits that implement CONFIG_CMD_FS_GENERIC are in u-boot/master but not yet in u-boot-arm/master. So, Tegra's master branch can't simply be based on current u-boot-arm/master, since if it was, applying my patch would break functionality until it was merged with u-boot/master and so picked up the actual implementation.
Hopefully, u-boot-arm/master will merge in (or get reset to) u-boot/master fairly shortly. However, should Tegra's repo have to wait for this?
Instead, I propose that 2nd-level custodians should be able to do something like:
# (in u-boot-tegra.git, assuming everything is merged already) git checkout master git reset --hard u-boot/master git am patch_that_depends_on_uboot_master # send pull request to u-boot-arm/master
# (in u-boot-tegra.git, assuming some patches already applied locally) git checkout master git merge u-boot/master git am patch_that_depends_on_uboot_master # send pull request to u-boot-arm/master
This should work fine provided that u-boot/master and u-boot-arm/master guarantee never to rebase. If they don't make that guarantee, then I don't think we can be using merges at all anyway, so that shouldn't be an issue.
What do people think?