* - function must not modify anything other than
* its return value (for cost computation functions, COST()) or
* its designated output (for precomputation functions, PRECOMP())
* - function must not modify anything other than
* its return value (for cost computation functions, COST()) or
* its designated output (for precomputation functions, PRECOMP())
* secdatasz, passed as secdata, uninitialised on entry.
* After all the copies have finished, `combine' is invoked
* nsections times sequentially, with the same sets of arguments.
* secdatasz, passed as secdata, uninitialised on entry.
* After all the copies have finished, `combine' is invoked
* nsections times sequentially, with the same sets of arguments.