On Tue, 16 Nov 2010 02:15:45 +0100, Ian Hickson <i...@hixie.ch> wrote:
On Wed, 11 Aug 2010, Boris Zbarsky wrote:
For what it's worth, as I see it there are three possible behaviors for
a javascript: URI (whether in an attribute value or elsewhere):
1) Don't run the script.
2) Run the script, but in a sandbox.
3) Run the script against some Window object (which one?)
Defining which of these happens in which case would be good. Again,
Gecko's behavior is #2 by default (in all sorts of situations; basically
anywhere you can dereference a URI), with exceptions made to do #3 in
some cases.
That's what the spec says currently.
I've recently had reason to dabble with inline javascript: URLs in Opera,
trying to figure out what the interoperability constraints are.
Opera's current behavior is to execute javascript: URLs except for in the
context of <img>, <embed>, <applet> and any inline loads from CSS.
Before I was aware of this thread, I went through the different kinds of
contexts where we do allow javascript: to execute, comparing to other
browsers. The results:
<video poster="javascript:..."> only executed by Opera
<script src="javascript:..."> only executed by Opera
<bgsound src="javascript:..."> only executed by Opera
<object data="javascript:..."> only executed by Opera and Firefox
(I haven't looked at <iframe>, as we don't treat that as an inline load in
the same way as the above.)
Based on this, unless there are corner-cases I've missed, it seems
unlikely that there's a large body of web content that depends on inline
javascript: URLs executing. My current plan is to try completely blocking
javascript: URLs in the contexts mentioned above. This seems to be the
simplest to implement and the fastest way to reach interoperability. The
alternative is to start executing javascript: URLs in more contexts,
which, even if sandboxed, doesn't seem particularly useful.
I'll keep you posted if there are any compatibility issues that come up
with this. Assuming (boldly) there is not, would there be support from
other browsers to move in this direction and change the spec to match? (It
seems that IE and WebKit are already basically already doing what I'm
advocating.)
--
Philip Jägenstedt
Core Developer
Opera Software
