1287659 - [e10s] pageAction.show from certain webNavigation listeners is too early to have an effect

Status: RESOLVED INCOMPLETE

(WebExtensions :: Untriaged, defect, P3)

Description

[Rob Wu [:robwu]]

1. Enable e10s.
2. Visit example.com
3. Load pageAction-webNavigation.zip at about:debugging (from https://bugzilla.mozilla.org/show_bug.cgi?id=1287649)
4. Refresh example.com

Expected (without e10s):
- The page action should be shown.

Actual (with e10s):
- The page action does not show up.

Extra info:
- This seems like a race condition / timing issue. When I open the browser toolbox and put a breakpoint at [1] before step 4, then the page action is shown when I resume execution.


[1] http://searchfox.org/mozilla-central/rev/bfcc10319e4e3ce78367fa9bba9316f7eb5248b6/browser/components/extensions/ext-pageAction.js#91

Comment 1

[Luca Greco [:rpl] [:luca] [:lgreco]]

This issue has a connection to what I described in Bug 1287649:

the pageAction API clears the pageAction on every location change, the webNavigation.onCommitted event happens before the location change,
and so the pageAction API implementation hides the pageAction after that the callback registered to webNavigation.onCommitted calls pageAction.show).

(And by setting a breakpoint in the callback registered to the webNavigation API events, as a side-effect we are executing pageAction.show after the pageAction API has already reacted to the location change)

Comment 2

[Firefox Bug Husbandry Bot]

With Firefox 57 only WebExtensions are permitted and are, by default, e10s compatible.