I just realised that since Confluence 5.10 the build numbers as returned by GeneralUtil are no longer updated in each release. Instead they tend to stay the same for all bugfix releases of a minor version.
Apparently the marketplace build number is now the unique build number. Unfortunately the GeneralUtil has not been updated to reflect this change and does not seem to expose the marketplace build number at all.
This means we cannot keep for example 6.5.0 and 6.5.2 apart from each other by looking at the build number.
What is the best approach for this?