Runs a database mutation with undo support when not already inside a command transaction.
When a command has started an undo transaction via AcEdCommand.trigger, the callback runs directly to avoid nested undo marks.
Database to mutate.
Undo group label shown in the undo stack.
Mutation callback.
The value returned by fn.
fn
Runs a database mutation with undo support when not already inside a command transaction.
When a command has started an undo transaction via AcEdCommand.trigger, the callback runs directly to avoid nested undo marks.