Details
Major Description
When a response returns a content-location header, flushLocationCacheEntry is invoked on the content-location's URL. flushLocationCacheEntry causes the cached entry to be flushed if the entry is older than the response and the etags differ.
However, the response and entry ETags are not considered different if either ETag header values are null(see:CacheInvalidator.responseAndEntryEtagsDiffer). This causes the resource referenced by the response's content-location header to remain cached.
I'm not familiar with the HTTP spec, but the responseAndEntryEtagsDiffer, ETag null checks seem iffy.
The same problem effects 4.2.5 as well.
**Relevant code
***From CacheInvalidator.flushInvalidatedCacheEntries:
final URL contentLocation = getContentLocationURL(reqURL, response);
if (contentLocation != null) {
flushLocationCacheEntry(reqURL, response, contentLocation);
}
***From CacheInvalidator.flushLocationCacheEntry
if (responseDateOlderThanEntryDate(response, entry)) {
return;
}
if (!responseAndEntryEtagsDiffer(response, entry)) {
return;
}
***From CacheInvalidator.responseAndEntryEtagsDiffer:
if (entryEtag == null || responseEtag == null) {
return false;
}