Prepared request gets stuck in error state

[chdh]

When an SQL error occurs after calling connection.execute() with a prepared request, the error state remains active and connection.unprepare() or further connection.execute() calls result in the previous error.

Test case: testPrepare.zip

Workaround: Reset the error state explicitly by executing request.error = undefined.
This is done when the doResetError flag is set in the test case.

Console output of the test case with doResetError = false:

openConnection()
prepareRequest()
Request prepared.
executeNextRequest() 1
Request 1 completed.
executeNextRequest() 2
Request 2 failed: Error: Divide by zero error encountered.
executeNextRequest() 3
Request 3 failed: Error: Divide by zero error encountered.
unprepareRequest()
unprepare failed: Error: Divide by zero error encountered.
closeConnection()
Connection ended.

Console output of the test case with doResetError = true:
(This is the expected behavior)

openConnection()
prepareRequest()
Request prepared.
executeNextRequest() 1
Request 1 completed.
executeNextRequest() 2
Request 2 failed: Error: Divide by zero error encountered.
executeNextRequest() 3
Request 3 completed.
unprepareRequest()
unprepare completed.
closeConnection()
Connection ended.

[arthurschreiber]

See #1717.