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Scenario: nested-default-branch

A nested splice's .splice without default-branch means the same branch in the monorepo as in the upstream it came from.

  • Monorepo: empty, default branch main.
  • Outer upstream ($UPSTREAM): default branch master. It uses git-splice itself: the inner upstream is spliced in at b/.
  • Inner upstream ($UPSTREAM-b.git): default branch master too, so b/.splice doesn't name a default branch.

A .splice without default-branch means: the upstream's default branch has the same name as the default branch of what the splice lives in. In the outer upstream, that's the repository, with master. In the monorepo, it's vendor/a/, which stands in for the outer upstream there, and whose default branch is master too. So b/ syncs with master in both places, as it would in a separate clone of the outer upstream. Before, a .splice without default-branch followed the monorepo's default branch, main, which the inner upstream doesn't have (#71).

clone and init inside a splice follow the same rule: they record default-branch only if the new upstream's default branch differs from the one of the splice above. So the file means the same in both directions. init around a splice records the branch the splices inside followed, where the new one's differs (made around).

Output​

setup.bash builds this state:

$ build_scenario scenario_nested_default_branch https://git.example.com/b.git

In a plain clone of the outer upstream​

As a separate folder with a clone of the outer upstream would have it, b/ syncs with master:

$ git clone -q "$UPSTREAM" ../a-clone &&
>   git -C ../a-clone splice fetch
ok   b fetched
$ git -C ../a-clone splice status
On branch master

  up to date  b

In the monorepo​

clone records the outer upstream's default branch, since it differs from the monorepo's:

$ git splice clone "$UPSTREAM" vendor/a
===  vendor/a: fetching $UPSTREAM
ok   vendor/a: cloned ddf42f3 from master
$ git splice fetch
ok   vendor/a fetched
ok   vendor/a/b fetched
$ git config --file vendor/a/.splice upstream.origin.default-branch
master

vendor/a/b/.splice came along unchanged, without one:

$ git config --file vendor/a/b/.splice upstream.origin.default-branch
[1]

So on the monorepo's main, both sync with master:

$ git splice status
On branch main

  up to date  vendor/a -> master
  up to date  vendor/a/b -> master

A change to vendor/a/b/, pushed from main, goes to master in the inner upstream, which has no other branch:

$ echo "b local" >>vendor/a/b/file.txt &&
>   git commit -q -a -m "b local" &&
>   git splice push vendor/a/b
ok   vendor/a/b: pushed 701ab17 to master
$ git -C "$UPSTREAM-b.git" for-each-ref --format='%(refname:short)' refs/heads
master