Created attachment 251662 [details] Testcase -- there should be 4 alerts We should be looking for listeners on the kid, not the parent.
Created attachment 251665 [details] [diff] [review] Fix
Testcase is not valid, because capturing listeners shouldn't fire on target (Bug 235441).
This appears to be a pretty straightforward bug fix in material that's not presently documented in a meaningful way anyway. What sort of documentation is needed for this (I'm curious since the dev-doc-needed keyword is set)?
I've added a note of this bug fix to the Fx3 for developers page; tagging as doc-complete.