753542 - Add prefs to enable/disable E4X (javascript.options.xml.content and .chrome)

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Comment 1

[Jason Orendorff [:jorendorff]]

Attachment: WIP 1, part 1 - Rename JSOPTION_XML -> JSOPTION_MOAR_XML and other renaming

The problem is that JSOPTION_XML doesn't do what you might guess, so I'm splitting it into two separate options:

    JSOPTION_ALLOW_XML - if this is off, we won't allow E4X syntax
      no matter what your version number is
    JSOPTION_MOAR_XML - if ALLOW_XML is off, this has no effect;
      if ALLOW_XML is on, this has the effect of the existing JSOPTION_XML flag,
      which means we allow E4X even in JS version numbers that don't
      normally have it, and <!-- is treated as an E4X comment rather than
      as a // to-end-of-line comment.

This patch simply renames the existing JSOPTION_XML to JSOPTION_MOAR_XML,
and a few other trivial renamings/cleanups. There should be no change in behavior.

Comment 2

[Jason Orendorff [:jorendorff]]

Attachment: WIP 1, part 2 - JSOPTION_ALLOW_XML

Adds JSOPTION_ALLOW_XML and unconditionally turns it on throughout the browser (and JS test suites except jsapi-tests).

Comment 3

[Jason Orendorff [:jorendorff]]

Attachment: WIP 1, part 3 - add prefs for E4X support

This adds two prefs:
  javascript.options.xml.chrome
  javascript.options.xml.content

Both these prefs control JSOPTION_ALLOW_XML. The first is for chrome JS; the second is for web content.

In this patch, both default to true so as not to change the default behavior, but in a follow-up bug I intend to make them both off-by-default!

Note: In this WIP, the prefs only control XML syntax; neither pref affects the constructors XML, XMLList, Namespace, etc. that exist in every global. Those shouldn't exist either, if JSOPTION_ALLOW_XML is off. I just haven't implemented that part yet.

Comment 4

[Jason Orendorff [:jorendorff]]

Oh - I should add that due to bugs in part 2, this isn't passing tests yet. At the moment, it's disabling XML support more than it should. Just putting the patches up early so anyone interested could look into the effect on addons.

Comment 5

[Jason Orendorff [:jorendorff]]

https://tbpl.mozilla.org/?tree=Try&rev=34c01d5ee00e

Comment 6

[Jason Orendorff [:jorendorff]]

Attachment: v2

Comment 7

[Jason Orendorff [:jorendorff]]

Attachment: v3 - also check the pref in dom/workers

Sorry for the last-minute request. I'd like addon developers to be able to test their stuff using FF15 this release, and default the pref to false in FF16.

Comment 8

[Jason Orendorff [:jorendorff]]

New Try run, since I added code:
  https://tbpl.mozilla.org/?tree=Try&rev=b96dd38052fa

Comment 9

[Jason Orendorff [:jorendorff]]

Thank you for the rapid reviews!

https://hg.mozilla.org/integration/mozilla-inbound/rev/ce0c716baefd

Comment 10

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/ce0c716baefd