This is not accurate.
There was, indeed, testing on the testnet with a full (1 MB) block. This was accepted by both the 0.7 and 0.8 versions. There is no concern here.
Slush's block should have produced the same valid block. However, the block was structured carefully as to expose a problem in 0.7 that was never discovered. Not only was this an extremely difficult problem to catch, but its finding would in fact not have been accelerated with a mixed testnet. The introduction of 0.8 into the equation would actually delay finding the bug, as it would mean less time spent testing edge cases on 0.7.
Source?
@dree12: Do you mean it was done on purpose? Source?
From IRC, all said by gmaxwell:
I'd rather it go to the 250k level while we don't know. I'm not certian that it couldn't be triggered by a somewhat smaller block.
Seems to indicate that smaller blocks could trigger it.
or 0.7 had another dumb implicit limit + which we didn't discover because our tests were inadequate to discover + and miners were encouraged to crank their block targets up when other than a few testnet blocks only a few max size blocks had ever been created.
Testnet blocks were at max size, so that type of testing could not have caught the issue.
There are some with >2000 TXN and such, but they don't have large numbers of txins because I was spending 50 tnbtc blocks.
This seems to indicate that not even a large number of transactions specifically causes the issue, but rather a large number of txins.
we don't have it fully measured and determined yet, but its most likely the number of transaction outputs being spent plus the number of outputs being created.
This supports the idea that only specific blocks could cause this.
we have tests that make maximum sized blocks... but not one that makes large numbers of both inputs and outputs.
In conclusion, it seems that it was not in fact a "big block" that caused this. A small block could in theory cause it if the tx-ins or tx-outs were small, which is entirely possible thanks to compressed public keys.
I did not mean my statement "structured carefully" to mean that someone has intentionally done so, but rather that the block's structure was rare and unique.
