title: Npgsql does not commit transaction after failed command
body: <p>I'm using Npgsql 2.0.11 under .NET 4.0 to modify a PostgreSQL 9.0 database. The program makes many modifications to the database, all within a single transaction.</p>
  
  <p>Just before committing, I run SELECT statement, which sometimes fails (eg. with a timeout). I swallow the exception and go ahead and commit the transaction anyway. There is no error, so it appears as if everything worked, but in actual fact the database was not modified at all!</p>
  
  <p>My guess is that the failed SELECT rolled back the entire transaction. Can I either prevent this (ie. have the transaction still committed) or at least detect this situation and throw an exception, so the user knows the commit failed?</p>
  
  <p>I know that in this specific case I could just move the SELECT outside the transaction, but I'm more concerned about solving this for the general case. Having a commit not commit is a pretty serious problem and I want to make sure it doesn't go undetected.</p>