Reported by jteh on 2015-04-14 06:57
(Spun off #308.)
While downgrading is generally discouraged, it does happen. When upgrading, we can (and should) unregister the previous install using the version being installed, as newer versions will always know about the past. However, when downgrading, this is bad because the version being installed (the downgrade) may fail to unregister something registered by a later version. This can cause severe issues in extreme cases; e.g. #308, where it could cause a security issue. Therefore, when downgrading, we should unregister the installation using the previous copy (the one we're about to overwrite).
Detecting downgrades is non-trivial due to snapshots. The best we can probably do is check the date of the executables.
Blocking #308
Reported by jteh on 2015-04-14 06:57
(Spun off #308.)
While downgrading is generally discouraged, it does happen. When upgrading, we can (and should) unregister the previous install using the version being installed, as newer versions will always know about the past. However, when downgrading, this is bad because the version being installed (the downgrade) may fail to unregister something registered by a later version. This can cause severe issues in extreme cases; e.g. #308, where it could cause a security issue. Therefore, when downgrading, we should unregister the installation using the previous copy (the one we're about to overwrite).
Detecting downgrades is non-trivial due to snapshots. The best we can probably do is check the date of the executables.
Blocking #308