Unable to login to the publisher and store portal user having username with special characters

[SiluniPathirana]

We observed that username with special characters like ' (apostrophe) was unable to login to the publisher and store portal. And throwing the following exception

Caused by: org.wso2.carbon.registry.core.exceptions.RegistryException: The path '/_system/governance/users/TEST2.COM:up'si' contains one or more illegal characters (~!@#;%^*()+={}|<>"',)
at org.wso2.carbon.registry.core.jdbc.Repository.put(Repository.java:262)
at org.wso2.carbon.registry.core.jdbc.EmbeddedRegistry.put(EmbeddedRegistry.java:717)
at org.wso2.carbon.registry.core.caching.CacheBackedRegistry.put(CacheBackedRegistry.java:591)
at org.wso2.carbon.registry.core.session.UserRegistry.putInternal(UserRegistry.java:828)
at org.wso2.carbon.registry.core.session.UserRegistry.access$1000(UserRegistry.java:61)
at org.wso2.carbon.registry.core.session.UserRegistry$11.run(UserRegistry.java:804)
at org.wso2.carbon.registry.core.session.UserRegistry$11.run(UserRegistry.java:801)