Race condition potentially causing auto-update to be disregarded at launch time

[gwarser]

Prerequisites

• I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
• This is not a support issue or a question
  • Support issues and questions are handled at /r/uMatrix
• I tried to reproduce the issue when...
  • uMatrix is the only extension
  • uMatrix with default lists/settings
  • using a new, unmodified browser profile
• I am running the latest version of uMatrix
• I checked the documentation to understand that the issue I report is not a normal behavior

Description

uMatrix may update assets even if "Auto-update assets" is unchecked

Steps to Reproduce

1. install uMatrix in fresh Firefox profile
2. go to Dashboard and uncheck "Auto-update assets"
3. close Dashboard, close browser
4. reopen browser, open console (adjust filter to show xhr)
5. assets will start updating after ~7 minutes

Notes

Logging line added just before µm.scheduleAssetUpdater here https://github.com/gorhill/uMatrix/blob/db7feed9c5558933aa4962525072c4b1d04633d2/src/js/start.js#L56

console.log('µm.userSettings.autoUpdate', µm.userSettings.autoUpdate);

will print

µm.userSettings.autoUpdate true

to the console if Firefox run with -jsconsole parameter.

You can check auto-update, restart, uncheck, restart, and console will always print true.

This may (will?) eventually fix itself, but I don't know how yet. (I somehow manged to switch it to false but don't know how.)

See also https://old.reddit.com/r/uMatrix/comments/9d8dd9/two_bugs_in_umatrix/

Your environment

• uMatrix version: 1.3.14
• Browser Name and version: Firefox ESR 60.2.1, Nightly 20180925100100
• Operating System and version: Mint 18.3

[gorhill]

Looks like a race-condition -- scheduleAssetUpdater is being called before user settings are confirmed to be loaded, and hence uMatrix ends up using the default value for autoUpdate.