fix number of sub_draws used

Revert of 5424fde7

added bug label

Can you provide a bit more explanation in the commit message? In particular, why is it necessary now to revert a commit that was made 7 years ago? Also, why only on the 6.x (I suppose it’s been fixed in another way on the master branch).

The commit 7 years ago was wrong. Commit fd807372 introduced the behavior documented in the manual. 5424fde7 inadvertently went back to the prior behavior, which is wrong. The fix for master is in !2318 (merged).

I should add that the problem is probably not too relevant. With default settings, it affects chains that have fewer than 4800 draws.

mentioned in commit d701fa5c

merged