1225211 - Timeout fire before the “click” event loop is complete

Status: UNCONFIRMED

(Core :: DOM: Core & HTML, defect)

Description

[hdd2008]

User Agent: Opera/9.80 (Windows NT 6.1; WOW64) Presto/2.12.388 Version/12.17

Steps to reproduce:

http://stackoverflow.com/questions/33741170/why-does-the-timeout-fire-before-the-click-event-loop-is-complete-on-firefox

http://jsfiddle.net/pLezf4ar/


Actual results:

alert shows 10


Expected results:

alert shows 0

Comment 1

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

From the stackoverflow thread:
"Because unlike many browsers, Firefox may allow the JavaScript thread to run other code while the alert, prompt, and confirm modals are showing, suspending the current code. [...]

I would expect [...] that Mozilla will change this to be in line with other browsers, as one could argue it violates JavaScript's run-to-completion semantics for tasks, and those semantics just got beefed up and clarified by the latest specification."

Comment 2

[Boris Zbarsky [:bzbarsky]]

This has nothing to do with the JS engine, which doesn't even have an event loop in Firefox so far.  alert() and confirm() are pure DOM code.