Mozilla Developers Hate Saved HTML Manuals

My website, Cyclopath, is written in Flex, Adobe's development environment which produces apps that run in the Flash Player. Needless to say, I occasionally need to reference the Flex documentation, which is HTML. I can browse it either on Adobe's website (slow) or save their zip file and browse it off the hard disk (fast). Guess which I chose?

Anyway, recent versions of Firefox 3 break these docs, because they don't allow different files in the doc package to reference needed JavaScript (because it's in a higher directory), so all the helpful links like "Show Inherited Public Properties" don't work.

And here's the error message that shows up in the error console:

Error: uncaught exception: [Exception... "Security error" code: "1000" nsresult: "0x805303e8 (NS_ERROR_DOM_SECURITY_ERR)" location: "file:///export/scratch/reid/flex3.2.0/doc/langref/asdoc.js Line: 493"]

...impossible to Google. Bah.

Wandering around the Mozilla bug database a little (using, frankly, a lot of expertise that most people don't have) revealed that, in fact, this is by design.

You can turn off the behavior by going to about:config and setting the secret configuration variable security.fileuri.strict_origin_policy to false. Mozilla developers are not interested in making this more obvious and don't believe that anyone other than a web developer needs to change it, despite the large installed base of on-disk HTML user manuals for a variety of things.

I don't fully understand the security reasons for this change. I assume they're sound. But what an absurdly opaque failure mode.

Shame, Mozilla!