Foreign entries are necessary to guarantee that an HTML file with manifest attribute will be associated with an appropriate cache, not a random cache that has this resource. Whenever it is detected that an HTML file in a cache should be associated with a different cache, the entry is marked as foreign, and will no longer be used for loading a main resource.
Currently, they are basically unimplemented, although there are bits of related logic in code.
Created attachment 26637 [details]
Created attachment 26638 [details]
Forgot to save ChangeLog before making the patch.
Comment on attachment 26638 [details]
Committed revision 39884.