Branches and databases from the preview's earlier shapes are not
supported, and such branches are recreated. The earlier shapes are the
copy model, where a branch file kept its own data payload, and the
tables registered as 0150-add-file-branch-table,
0152-add-file-branch-table and 0153-add-file-pull-request-tables. This
commit removes the code that existed only for them. A fresh database
ends with the same schema as before.
- 0155-add-file-branch-table.sql loses its header about the old
registrations, every IF NOT EXISTS, and the base_branch_revn upgrade
and backfill. CREATE TABLE file_branch already declares the column.
- 0156 and 0157 lose every IF NOT EXISTS.
- 0158-add-file-branch-change-data-version folds into 0157, and its
file and registration go. CREATE TABLE file_branch_change declares
data_version NOT NULL, because both writers of the op log, a branch
save and the squash of an update from main, stamp every row.
- need-migration-to? loses its nil case, which replayed an unstamped
op-log row at the base's version, and the branch derive loses the
comment that described it. Stamped rows replay as before.
- The tests for a re-run of the branch table migration and for the
replay of an unstamped row go, with the require the first one used.
A database that holds the preview's older shapes must drop its
branching tables and the file.is_branch column, and delete the
branching steps from its migrations table, before it boots this code.
A database that ran 0157 without 0158 lacks data_version and counts as
an older shape. A database that already ran 0155 to 0158 under these
names keeps working, because a migration runs once per name.
AI-assisted-by: claude-opus-5-5
1410d66ca2