Store UserOptions in DbConnectionPool.PendingGetConnection

[stephentoub]

@roji, is this worth fixing? It does seem like these were supposed to be stored such that they'd be passed through to subsequent operations, but this code has also been around for a very long time.

[roji]

This actually has people who know what's going on, /cc @David-Engel @maryamariyan @Wraith2. It definitely does look like this could be a bug.

[divega]

Also cc @cheenamalhotra. Microsoft.Data.SqlClient likely has a copy of the same code with the same potential bug.

[cheenamalhotra]

Thanks @divega

I have ported over this change to Microsoft.Data.SqlClient. Strangely this issue also existed in NetFx source code, seems like a miss from long time.

[divega]

It seems to exist on every copy of the code (there a separate copy for each provider) in this repo. I think we need someone to dive a bit deeper to understand the ramifications of both the original (apparently buggy) code and of taking this change.

[cheenamalhotra]

I looked into the property usage and seems like this PR is not going to add any value, the userOptions property is passed all the way to DbConnectionFactory:L372 after which it disappears.

Implementation in SqlClient also treats it as null: SqlConnectionFactory:L31 and SqlConnectionFactory:L34

[stephentoub]

Ok. I'll close this... but if it's actually not going to add value, it would seem instead there's some dead code here to be deleted.