Fix "Page not found" suggested search path

[harrisi]

Summary

When a page is not found, a "Page not found" page is served, with a section for suggested search terms by generating links to window.location.pathname.split('/').map(el => `https://developer.mozilla.org/${window.location.pathname.split('/')[1]}/search?q=${el}`).splice(2) (this is obviously not how it's actually done on the server, but just to show what's happening). This is includes the top-most level of the path, which either shouldn't be included in the links generated, as it causes the path to be something like https://developer.mozilla.org/docs/search?q=Quirks%20Mode%20and%20Standards%20Mode, with docs included, whereas the search path is just /search (i.e., top-level).

URL

https://developer.mozilla.org/docs/Web/HTML/Quirks_Mode_and_Standards_Mode

Reproduction steps

1. Navigate to https://developer.mozilla.org/docs/Web/HTML/Quirks_Mode_and_Standards_Mode
2. Click on any link in the suggested search section

Expected behavior

Should navigate to https://developer.mozilla.org/en-US/search?q=Quirks%20Mode%20and%20Standards%20Mode

Actual behavior

Navigates to https://developer.mozilla.org/en-US/docs/search?q=Quirks%20Mode%20and%20Standards%20Mode

Device

Desktop

Browser

Firefox

Browser version

Stable

Operating system

Mac OS

Screenshot

No response

Anything else?

No response

Validations

• I have read the Community Participation Guidelines.
• I have verified that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• I have checked that this is a concrete bug. For Q&A open a GitHub Discussion.

[caugner]

@harrisi Would you have another example?

For me, the URL you mention redirects to /en-US/docs/..., as it should be:

% curl -i https://developer.mozilla.org/docs/Web/HTML/Quirks_Mode_and_Standards_Mode                                                                                
HTTP/2 302 
cache-control: no-store
location: /en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode
vary: Accept
content-type: text/plain; charset=utf-8
date: Wed, 10 May 2023 14:52:17 GMT
server: Google Frontend
content-length: 73
via: 1.1 google
x-cache: miss
alt-svc: clear

Found. Redirecting to /en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode

[harrisi]

Interesting. I just tried this with curl and Chrome and I do indeed get redirected to the proper en-US page.

It seems the issue is that I'm logged into MDN Plus on Firefox. I'll look into that more.

[caugner]

It seems the issue is that I'm logged into MDN Plus on Firefox.

Do you have MDN Offline enabled by any chance?

[harrisi]

Yes, which does seem to be the issue. That seems like a big enough difference in cause to warrant a new issue.

[caugner]

@harrisi This seems to have been fixed with #8846, I can not reproduce it (with MDN Offline enabled). Would you mind trying it again? (I tested with https://developer.mozilla.org/docs/Web/HTML/Quirks)

[harrisi]

I'm still seeing this. I tried clearing my cache and getting rid of any local storage, redownloading, and testing again. Tried in a different browser, in private mode, still seeing the issue.

Interestingly, if I sign in in a Safari private window, turn on offline content, and before even downloading the content, navigate to https://developer.mozilla.org/docs/Web/HTML/Quirks_Mode_and_Standards_Mode, I see the issue. If I turn off offline content and go to the address again, it redirects correctly.

I'm still not sure how to even effectively recreate this locally, actually. Any tips on mocking a signed in user, using local storage rather than local web server, etc. would be appreciated.

[caugner]

Thank you for the update. Can you explain how you navigate to https://developer.mozilla.org/docs/Web/HTML/Quirks_Mode_and_Standards_Mode in the first place (and not https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode, which would work)?

[harrisi]

1. Open a page that is in quirks mode (or Almost Standards mode) in Firefox (e.g., https://www.quirksmode.org/)
2. View console output
3. Click on [Learn More] in console

[caugner]

Added effort: large, as the only solution I see is to add redirect support to MDN Offline. If we only add the missing locale (ignoring the _redirects.txt in content), then this could be effort: medium.