In classic I needed a 3-state.

1. not active
2. active, waiting for > 1MB block
3. active

If you follow that I think you can delete some more overhead elsewhere.

In D479#8388, @zander wrote:

In classic I needed a 3-state.

1. not active
2. active, waiting for > 1MB block
3. active

If you follow that I think you can delete some more overhead elsewhere.

That's actually a very strong approach.

I promise to make this change after this simpler approach gets approved. I also think perhaps existing logic will get simplified a little. I know 1 function in particular that can get much simpler.. or at least simpler to read.

The flag should not really be necessary in my view, although I can live with it as an interim measure.

I've added D480 which introduces a checkpoint for the mainnet UAHF fork block.
This could be used to simplify the check whether we are pre-fork or post-fork to one involving only block height.
Then we should be able to do away with it with this flag again.

In D479#8414, @freetrader wrote:

The flag should not really be necessary in my view, although I can live with it as an interim measure.

It's not strictly, necessary, no, but it saves on having to lock cs_main to check chianActive.Tip()->nHeight, which one would have to do without the flag. See D478 where such a check is made without needing to hold a lock.