I don't know of any observable bug that this fixes, but the code without this fix seems incorrect; the "removed sentinel" concept generally requires that callers enumerating transitions check that they're not enumerating the sentinel. This ensures that HasAnimationOfProperty switches from returning true to false in the first refresh cycle after the end of the animation rather than the second. I originally wrote this in https://bugzilla.mozilla.org/show_bug.cgi?id=876626#c13 but it turned out not to be related to that bug.
Created attachment 784705 [details] [diff] [review] Make HasAnimationOfProperty return false in the refresh driver tick in which the transition completes.
Attachment #784705 - Flags: review?(ncameron)
Status: NEW → RESOLVED
Last Resolved: 4 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla26
You need to log in before you can comment on or make changes to this bug.