Some pages can freeze Firefox when Karma Blocker is enabled

[t-bone]

Not with the default rule set, but with the rule set I actually use, at a minimum, this page will freeze Firefox, requiring a hard kill, when loaded:

•  http://www.downloadsquad.com/2008/08/05/5-apps-you-run-that-suck-and-5-replacements-that-dont/

[t-bone]

This is the smallest complete rule set that continues to exhibit this behavior:

[Settings]
threshold=2

[Group]
name="Third-party"
score=1
rule=$thirdParty==true

[Group]
name="Keyword: ad"
score=1
rule=$url=~'\bad'
rule=$url=~'ads?\b'

When navigating to this page, nothing appears in the Karma Blocker monitor window. When it is happening, Firefox has the CPU pegged. This must be some sort of infinite loop.

[t-bone]

Looks like it's this recently introduced line:

fields.node.setAttribute('kabl', gKablCollapseMarker);

Removing it stops this behavior.

[t-bone]

Also happens at:

•  http://blogs.techrepublic.com.com/10things/?p=392

[t-bone]

(In [428]) Refs #182

• Do not set extended-collapse marker attributes on <style> nodes.