FB18756568 - Launching an app with an bundled Safari extension can reset the extension in Safari #66
Description
Steps to reproduce:
- Enable the StopTheMadness Pro extension (App ID 6471380298) in Safari
- Open https://example.org in Safari
- Open Activity Monitor and search for StopTheMadness
- Launch the StopTheMadness Pro app
Expected results: Nothing changes in Safari.
Actual results: (1) The StopTheMadness Pro (Safari) process quits and restarts with a new PID. (2) A duplicate extension content script is injected into every open Safari tab where the extension is enabled.
I don't know whether the bug is caused by merely launching the Mac app or by the Mac app's use of the API SFSafariExtensionManager getStateOfSafariExtensionWithIdentifier.
I was able to reproduce the bug in macOS Sequoia 15.5, Sonoma, and Ventura with Safari 18.5, as well as macOS Monterey with Safari 17.6.
The bug doesn't occur all the time. It does always happen after you update the extension app in the Mac App Store, and continues to occur for some time afterward, even after you quit and relaunch Safari multiple times. At some indeterminate point, the bug seems to stop happening, until you update the extension app again.
In the console log, I see the message "Could not signal service com.underpassapp.StopTheMadnessPro.SafariExtension".
Attached is a screen recording demonstrating the bug.
For more details and discussion, see the blog post https://underpassapp.com/news/2025/6/6.html
Related bugs: FB18755809 Disabling and re-enabling a Safari extension creates duplicate content scripts in open Safari tabs