Hot Standy introduced problem with query cancel behavior

The JDBC driver's regression test suite has revealed a change in behavior 
introduced by the hot standy patch.  Previously when a client sent a 
cancel request on an idle connection, nothing happened.  Now it sends an 
error message "ERROR: canceling statement due to user request".  This 
confuses the driver's protocol handling and it thinks that the error 
message is for the next statement issued.

Attached is a test case.

Kris Jurka