1964615 - when opening an *.shtml file locally FF spawns tabs endlessly and must be killed

Status: NEW

(Firefox :: File Handling, defect, P3)

Description

[znoteer]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:128.0) Gecko/20100101 Firefox/128.0

Steps to reproduce:

Firefox 128-ESR on Debian stable

1. Cloned a site with wget which made some *.shtml files locally and converted all internal links to function locally.
2. Opened the resulting index.shtml file and BOOM the unstoppable spawning of new tabs began

Actual results:

FF immediately began spawning new tabs without end. I was forced to quit FF. The same thing happened with a new profile. Renaming any existing *.html file on my system to *.shtml causes the same problem. Renaming the index.shtml file I downloaded with wget solved the problem.

Expected results:

I would have expected the shtml file to open normally without making Firefox spew tabs. Chromium opens shtml files normally. I found this bug (https://bugzilla.mozilla.org/show_bug.cgi?id=223212), but it is 22 years old and on Windows XP.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::File Handling' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Negritas Sergiu, Desktop QA]

Hello! Thank you for submitting this issue I have tried to reproduce the issue on my end but unfortunately I wasn't able to with firefox 140.0a1(2025-05-06) on Ubuntu 22.04
Could you please answer the following questions in order to further investigate this issue?

1. Does this issue happen with a new profile? Here is a link on how to create one: https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles
2. Does this issue happen in the latest nightly? Here is a link from where you can download it: https://www.mozilla.org/en-US/firefox/channel/desktop/
3. Do you have any addons installed? If yes could you please list them?
4. Could you please provide a screen recording or a screen shot with the issue?

Comment 3

[znoteer]

Attachment: FF-esr 128, new profile, endlessly spawning tabs on local .shtml file

Comment 4

[znoteer]

Attachment: screen recording FF nightly 140.0a1.en-US.linux-x86_64 endlessly spawning new tabs when opening local .shtml file

Comment 5

[znoteer]

(In reply to Negritas Sergiu, Desktop QA from comment #2)

Could you please answer the following questions in order to further investigate this issue?

1. Does this issue happen with a new profile? Here is a link on how to create one: https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles
2. Does this issue happen in the latest nightly? Here is a link from where you can download it: https://www.mozilla.org/en-US/firefox/channel/desktop/
3. Do you have any addons installed? If yes could you please list them?
4. Could you please provide a screen recording or a screen shot with the issue?

I've combined questions 1 and 4 in one video and 2 and 4 in another one. I tried to narrate but despite several tries I was unable to capture sound.

I'm using a tiling window manager, so the framing is a bit bizarre when a new window opens pushing others to the side, so you see 1.5 skinny windows instead of one wider window, but the important information is captured even if a bit confusing. You'll notice in one of the videos that I had to open the burger menu and select Quit several times to really make the spawning stop.

My understanding is that when you start FF with a new profile, the new profile does not contain any addons or extensions. That makes me wonder if you are still curious about my addons given I've shown this happens in a new profile. Please let me know if you want addon info.

Comment 6

[Marco Bonardo [:mak]]

This is probably just bug 1885804, or alternatively related to one of the See Also bugs in that bug report. There is in general an issue of infinite tab opening when Firefox hands off files to the OS that hands the file back to Firefox.