v1.9.3.0: Startup Bug Fix for Late Upgraders

This release fixes a bug for those who upgraded late to the recent consensus change (that change was released in v1.9.1.0).

It is required for anyone who tried to upgrade late to v1.9.1.0. If you tried to upgrade and it crashed, this is likely the reason why.

Technical Explanation

The following is for developers and the technically curious.

The cause was an attempt by the client to adjust wallet balances for a local blockchain reorganization during app initialization (startup). The problem is that the wallet has not been loaded yet at this stage of initialization, causing the program to crash. The technical underpinning is the dereferencing of a null pointer.

Incidentally, this is a class of startup bug that also affects the Explore API. Those fixes come in later commits, but should not affect users who rely on official releases for downloadable clients (typical users), because they wouldn't run the Explore API.