System versioning is dropped from temporal tables in ignored schemas

[IanKemp]

Title is pretty self-explanatory, if you have a temporal table called Bar in schema foo then specifying SqlPackageFilter=IgnoreSchema(foo) results in Bar's system versioning being dropped. The debug log output shows:

 -- checking filter for a SqlDropSystemVersioningStep

Looking in DeploymentStepDecider shows there's no explicit handling for Microsoft.SqlServer.Dac.Deployment.SqlDropSystemVersioningStep which is the issue. The simple fix (so far in my limited testing) is to check SqlDropSystemVersioningStep.Next and if that is a DropElementStep, pass the latter to DeploymentStepDecider.RemoveDropStep.

I will fork the repo and submit a PR tomorrow.

[IanKemp]

PR will not happen today, maybe only by next week as there are tests to write, in the meantime if anyone needs this fix desperately you can look at my WIP branch.

[t-johnson]

@IanKemp thanks for logging this and working to fix it - my guess is that you're the first who has tried to use this library against a DB with temporal tables setup.