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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.
  • a's upstream ($UPSTREAM): default branch master. It uses git splice itself: b is spliced in at b/.
  • b's upstream ($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 a's upstream, that's the repository, with master. In the monorepo, it's a, which stands in for a's 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 a's upstream. Before, a .splice without default-branch followed the monorepo's default branch, main, which b's 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.

Output​

setup.bash builds this state:

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

In a plain clone of a's upstream​

As a separate folder with a clone of a's upstream would have it, b syncs with master:

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

  up to date  b

In the monorepo​

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

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

b's .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 b, pushed from main, goes to master in b's 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