420603 - [FIX] Don't run script while setting up proto chain

Status: RESOLVED FIXED

(Core :: XPConnect, defect, P2)

Description

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

Once bug 401155 has landed the only (known) thing that can cause scripts to execute is while we set up the proto chain for the newly created wrapper.

Currently if the global property HTMLElement has a getter we'll execute that when wrapping any html element.

First off, does it really make sense to replace the prototype objects at all? Adding properties to them does make sense, but it seems like replacing them would just make things fail horribly.

Can we make them read-only properties? That would avoid people accidentally replacing them and making all new wrappers be borked.

At the very least we should make the code that sets up proto chains bail if any of the properties we're getting have getters and skip the rest of the proto chain.

I guess we could do this in a dot-release, but since it could in theory affect content (especially if we do the read-only thing) it would be really good to get into the release.

Comment 1

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

The first sentence should say:

that can cause scripts to execute *while wrapping* is while we set up the proto

Comment 2

[Johnny Stenback (:jst)]

Attachment: Fix.

This fixes the cases I've been able to find that might run scripts while we're wrapping a node. If others know of other places or know how to test for this I'd love to hear about it.

Comment 3

[Johnny Stenback (:jst)]

Not going to block on this one, but I'd still appreciate reviews...

Comment 4

[Johnny Stenback (:jst)]

Fixed. Note that the last hunk of that diff (formatting change only) doesn't apply against the trunk and should be ignored, it only applies against a local change here.