Currently
<style>::part(outer) {...}</style>
<custom-element1 partmap="inner outer">
<custom-element2>
# shadow
<span part="inner"></span>
</custom-element2>
</custom-element1>
Allows the span to be styled. This does not match the spec and it allows the author of document to style the span even though the custom-element1's author has not forwarded the part.
A correct example has the partmap on the inner CE.
<style>::part(outer) {...}</style>
<custom-element1>
<custom-element2 partmap="inner outer">
# shadow
<span part="inner"></span>
</custom-element2>
</custom-element1>
Comment 1 by bugdroid1@chromium.org
, Jul 3