There is as test that actually test for this (which we are failing, see Bowtie).

The failure is due to two reasons

1. The SchemaStorage::addSchema() method doesn't scan added schemas for an id property (at the same level as properties or type) which should be used in resolving refs. This is why we get errors about file_get_contents(http://localhost:1234/sibling_id/foo.json) failed.

2. When the id is altered for underlying schema this directly affects refs at the same level and the ones that have a shared parent. This is caused by the code here which adjust the base for ref's at the same level and even for other