508136 - ireflow can lead to Firefox never painting a new page

Status: RESOLVED WONTFIX

(Core :: Layout, defect)

Description

[Jesse Ruderman]

Attachment: testcase

1. Set the following environment variables:
  export GECKO_REFLOW_INTERRUPT_MODE=counter
  export GECKO_REFLOW_INTERRUPT_CHECKS_TO_SKIP=1
  export GECKO_REFLOW_INTERRUPT_FREQUENCY=1
2. Run Firefox.
3. Load a web page.
4. Drag the testcase (as a local file) into a Firefox window.

Result: old web page is still shown (zombie-like), but keypresses go to the testcase.  Possible spoofing risk?

The testcase is related to the one in bug 478527.

Comment 1

[Jesse Ruderman]

Would a web page be able to trigger this (with a different testcase) with the normal ireflow settings?

Comment 2

[Boris Zbarsky [:bzbarsky]]

> Would a web page be able to trigger this (with a different testcase) with the
> normal ireflow settings?

With the new setup, almost certainly not.  We set a timer to prevent OS event starvation, which should make sure that things get painted before we try reflowing again.

Comment 3

[Boris Zbarsky [:bzbarsky]]

And in particular, I think that this bug should be either invalid or wontfix, depending on how we want to think about it...

Comment 4

[Mats Palmgren (inactive)]

There's nothing to fix here afaict.