1417760 - On FireFox startup, webpage restored from previous session is loaded BEFORE webextensions are ready

Status: RESOLVED DUPLICATE of bug 1418030

(Firefox :: Session Restore, defect)

Description

[hundreAd]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:56.0) Gecko/20100101 Firefox/56.0
Build ID: 20171024165158

Steps to reproduce:

In Options: "When Firefox starts" set to "Show your windows and tabs from last time"; restart Firefox



Actual results:

When starting Firefox, it loads the previously-open tab before the webextensions are loaded, so it is not modified by them



Expected results:

This is undesirable in case of ad-blockers, HTTP referer changers, etc. (this is especially noticeable for pre-57 adblock plus extension, but still happens with 57 webextensions)

I'd like an optional setting to delay tab load until after the browser has finished processing all webextensions (obviously, at the expense of a slight slowdown on startup), otherwise the webpage is not modified (which is the reason for the webextension in the first place...) and I have to reload it manually to have it affected

note: those are not my webextensions, so I have no control over them