Bugzilla – Bug 20854
appcache : fallback entries need clarification on duplicates
Last modified: 2013-04-24 16:29:11 UTC
The reference http://www.w3.org/html/wg/drafts/html/master/browsers.html#concept-appcache-fallback needs to mention that fallback entries can't contain uri duplicates.
Use case : on first manifest visit, cookieless user agent may use url rewriting for resources, ie use a ";jsessionid=" trail or some other kind of session parameter. The uri + session trail seems to be the cache key at least on iOS devices.
The following manifest will cause Chrome 24 to fail loading the manifest, with a cryptic "Application Cache Error event: Failed to commit new cache to storage" error message :
This will fail because of the duplicate /fallback.php line. Removing the second one with ?sessionid fixes the problem. I believe Chrome does not know which fallback line to use.
That's just a bug in chrome. The spec allows "nested" fallback entries like this.
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Change Description: none
Rationale: A duplicate fallback namespace is just ignored as per spec, this is just an implementation error.