0002 migration exception fix should be patched on 3.X #617
Description
Our team recently undertook migrating constance from 2.9.1 to 4.X. Given the large jump in major versions, we opted to upgrade 2 -> 3 and 3 -> 4 in separate tranches.
Unfortunately, the implementation of migration 0002_migrate_from_old_table in versions older than 4.1.1 will silently fail when inserting rows into the newly-created table. We hit this particular scenario and due to the silent error, did not notice for some time. This resulted in configuration values being wrong / defaulted for a period of time until we were able to detect.
IMO, this upgrade scenario is a reasonable one (especially given how critical constance as a configuration tool is to applications that use it), and the fix in #579 should be back-ported to 3.X so that folks can safely migrate.