Missing entries in filter.xml

The calculation for the filter.xml of converted content packages can miss filters if the target is defined inside a content.xml. As an example, a content package with an entry like:

jcr_root/_oak_index/.content.xml
    <?xml version="1.0" encoding="UTF-8"?>
    <jcr:root ...
     ...
      <foo-index-1>
.....

and a filter.xml containing:

<filter root="/oak:index/foo-index-1/>

can generate a content package with a filter.xml missing the filter entry fo the index.