Michał Kępień authored Aug 24, 2018 and Mark Andrews committed Aug 27, 2018

The "exitcode" variable is set to 9 if a TCP connection fails, but is
not reset to 0 if a subsequent TCP connection succeeds.  This causes dig
to return a non-zero exit code if it succeeds in getting a TCP response
after a retry.  Fix by resetting "exitcode" to 0 if connect_done()
receives an event with the "result" field set to ISC_R_SUCCESS.