Firefox crashes when opening local HTML file (file size > 4MB)

[onmyouji]

BEFORE YOU BEGIN

I have attempted the following troubleshooting suggestions:

• [x] The issue persists when using Firefox in Troubleshoot Mode.
• [x] Disabled DNS-level content blocking (AdGuard Home, NextDNS, Control D, RethinkDNS, PiHole, etc), cleared my DNS cache, and used my ISP's DNS resolver (if applicable).
• [x] Cleared website data, restarted Firefox, and my issue persists.
• [x] I have created a new profile. The issue persists when using the current user.js file on GitHub. (Must be in a new profile and a new user.js!)

REPORT

Describe the bug Using Betterfox user.js causes Firefox to crash when opening local HTML file. The crash happens if the HTML file is larger than 4MB, smaller file doesn't cause crash.

To Reproduce

1. Create a fresh new profile.
2. Open a local HTML file that is bigger than 4MB. You can download this HTML file to your computer or use your own HTML file (> 4MB).
3. File will open normally.
4. Close Firefox, then put the user.js file to your profile folder.
5. Load Firefox, then open the local HTML file from your computer.
6. Your tab will crash and you get message "Gah. Your tab just crashed."

Expected behavior Firefox should not crash when opening a local HTML file from your computer.

Screenshots

Desktop (please complete the following information):

• OS: Windows 10 Home 64-bit Version 22H2 (19045.4046)
• Browser: Firefox
• Version: 123.0.1

[yokoffing]

I can reproduce. I will look into it.

Apparently this is happening in Waterfox as well:

• https://github.com/WaterfoxCo/Waterfox/issues/3254
• https://www.reddit.com/r/waterfox/comments/1aq7fgb/waterfox_tab_crashes_when_loading_an_html_file/

Update: I have confirmed it's reproducible in Floorp w/ Betterfox user.js.

Update: Does not occur in Librewolf.

[yokoffing]

@onmyouji Please reset the pref network.buffer.cache.size. It is causing the issue.

If you're starting with a new profile, remove that pref under Fastfox before applying the user.js.

[onmyouji]

Thanks, the issue was fixed after resetting it.

Should I close this issue or do you want to leave it open?

[yokoffing]

It’ll close once I push a release tomorrow.