[bctiemann]

Fixes: #728

The router sends the queries of a model that a plugin's resolver makes branchable to the branch, but provisioning copied only the tables of object types with the branching feature, plus their M2M through tables. A resolver-only model has no such object type, so its table wasn't copied, and its queries fell through to main's table.

Changes:

• get_tables_to_replicate() also includes the table of each registered model that isn't change-logged and that supports_branching() says is branchable, plus its M2M through tables, when any resolver is registered. Proxy, unmanaged and missing tables are skipped, and exempt_models still applies through supports_branching().
• docs/plugin-development.md: a resolver returning True also gives new branches their own copy of the model's table and its M2M through tables.

Tests:

• With a resolver registered for auth.Group, its table and auth_group_permissions are in get_tables_to_replicate(), and aren't when the model is exempt.
• A branch provisioned with that resolver has its own auth_group, and renaming a group or adding a permission to it in the branch leaves main's unchanged.
• Both fail on main.

Branches provisioned before this change still have no copy of these tables. That's the same situation as #683.

[bctiemann]

@claude /review and report only on actionable issues.

[github-actions]

Claude finished @bctiemann's task in 2m 17s —— View job

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Review

• Read changed files
• Analyze the implementation
• Post review findings

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The fix is correct and the approach is sound. One actionable issue and one minor note.

Actionable: M2M through tables of resolver-opted-in models are not replicated

utilities.py:344–354 adds only the model's own table. The existing path for change-logged models (lines 327–333) explicitly walks local_many_to_many and adds each through-table too. The new path skips that step.

For example, auth.Group has a permissions M2M to auth.Permission. Its through table (auth_group_permissions) won't be replicated, so any M2M write inside the branch (adding/removing permissions from a group) will land on main's auth_group_permissions, not the branch's copy. The test validates row-level isolation for the base table but doesn't exercise M2M fields, so this bug would go undetected.

Fix: after adding meta.db_table, walk model._meta.local_many_to_many the same way the change-logged loop does:

if (
    meta.db_table not in tables
    and meta.db_table in existing_tables
    and meta.managed
    and not meta.proxy
    and not issubclass(model, ChangeLoggingMixin)
    and supports_branching(model)
):
    tables.add(meta.db_table)
    for m2m_field in meta.local_many_to_many:
        if hasattr(m2m_field, 'through'):
            tables.add(m2m_field.through._meta.db_table)
        else:
            tables.add(m2m_field._get_m2m_db_table(meta))

Fix this →

Minor: addCleanup in test_changes_in_branch_stay_in_branch is redundant

ResolverModelBranchTestCase extends FastTeardownTransactionTestCase, whose _fixture_teardown already calls _drop_branch_schemas and drops every schema matching the branch prefix. The explicit self.addCleanup(self._drop_schema, branch.schema_name) on line 239 is harmless (DROP SCHEMA IF EXISTS no-ops on the second call) but adds noise.

[bctiemann]

Related, for the same release: #732 adds the missing-table check this PR has on its new loop to the existing object-type path of get_tables_to_replicate() (found via netboxlabs/netbox-custom-objects#1045). Kept as a separate issue so this PR stays scoped to #728.

[arthanson]

Just the one nit about imports, otherwise - nice work!

[arthanson]

these are being re-imported for no reason - I think the ChangeLoggingMixin is the only one that needs to be here