Prior to the fix the test would fail with NPE:

  Exception in thread "main" java.lang.NullPointerException
      at org.postgresql.jdbc2.AbstractJdbc2ResultSet.checkColumnIndex(AbstractJdbc2ResultSet.java:2619)
      at org.postgresql.jdbc2.AbstractJdbc2ResultSet.checkResultSet(AbstractJdbc2ResultSet.java:2637)
      at org.postgresql.jdbc2.AbstractJdbc2ResultSet.getInt(AbstractJdbc2ResultSet.java:2005)
      at org.h2.test.server.TestPGServer.testPrepareWithUnspecifiedType(TestPGServer.java:76)
      at org.h2.test.server.TestPGServer.test(TestPGServer.java:44)
      at org.h2.test.server.TestPGServer.main(TestPGServer.java:29)