With the recent discovery of a bug in the original ringCT code, and the subsequent update from using ASNL to Borromean Ring Signatures, how much testing has been done since that change, and what kind of fail safes are in place in case another bug is found and there is not enough time to patch and test the code? Is it at all possible to avoid the hard fork if it ever comes to that?
Sadly, most people will not help test on testnet. The changes pass all tests, and some low volume of transactions is flowing. The kind of bug that was found by RandomRun isn't a type of bug that can be detected by tests, however, unless you know the bug in the first place. The fork can't really be avoided now, it'd require a very quick update by pools, exchanges, and other important nodes, beyond the time needed to fix anything.