GatewayMappingService: fix Gateway selection...

[blook]

... for negative hashes

[yamt]

thank you for the patch.
the patch itself looks good to me. (well, it would be great if you can include a unit test)
but we usually use gerrit to submit patches, not github PRs here.
see https://github.com/midonet/midonet/blob/master/DEVELOPMENT.md#how-to-contribute

[blook]

thanks for your feedback. I submitted the patch on gerrit. Unfortunately I am not able to add a "tested" unit-test, because the current master is raising an exception while trying to run
gradlew midolman:test
Execution failed for task ':midolman:linkNativeFlowControllerTestGoogleTestExe'.

I would love to contribute to the project the 'right' way. Would it be ok for you to contact you via email for further details?

Regards

Sebastian

[yamt]

maybe you are seeing libgtest/c++ abi incompatibility.
cf. https://review.gerrithub.io/c/midonet/midonet/+/400020
if so, rebuilding libgtest for your env can be a workaround.