Openshift router does not respect ingress.kubernetes.io annotations

Openshift router does not respect ingress.kubernetes.io annotations, when tuned for kubernetes-ingress compatibility(https://docs.openshift.org/latest/admin_guide/managing_networking.html).

Version

$ oc version
oc v3.9.0+191fece
kubernetes v1.9.1+a0ce1bc657
features: Basic-Auth GSSAPI Kerberos SPNEGO

Steps To Reproduce

I'm using the same ingress controller resource for phpmyadmin(this application is a nice example to triage the issue), deployed on Tectonic with nginx-based ingress controller, using the following annotations:

  annotations:
    ingress.kubernetes.io/add-base-url: 'true'
    ingress.kubernetes.io/rewrite-target: /

and it works.
I've enabled the ingress compatibility on Openshift. Other applications work great, especially cookie session-affinity, but phppgadmin does not. The base-url is not getting added.

Current Result

ingress.kubernetes.io annotations are ignored

Expected Result

ingress.kubernetes.io annotations should be respected. These annotations are not nginx-specific, so should be supported across all ingress-controllers.