User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36

Steps to reproduce:

Try to add a search engine from an XML file

Actual results:

Console error:
Uncaught (in promise)
Exception { name: "NS_ERROR_FAILURE", message: "addEngine: Error adding engine:\n[Exception... "Invalid URI passed to SearchEngine constructor" nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)" location: "JS frame :: resource://gre/modules/OpenSearchEngine.jsm :: _install :: line 95" data: no]", result: 2147500037, filename: "resource://gre/modules/SearchService.jsm", lineNumber: 1861, columnNumber: 0, data: null, stack: "addOpenSearchEngine@resource://gre/modules/SearchService.jsm:1861:24\n", location: XPCWrappedNative_NoHelper }

Expected results:

Should have worked.

Somehow file: URLs are no longer permitted, see:
https://hg.mozilla.org/mozilla-central/rev/63167d041bb4#l21.133

So how do TB users add search engines these days? I noticed that in Daily there are only Google and DDG on offer these days.

Bug 1427317, attachment 9030183 [details] [diff] [review] was aiming at getting search engines online.

The quickest fix is to remove M-C code that checks for the http(s) scheme:
https://github.com/Betterbird/thunderbird-patches/blob/main/91/bugs/1718411-search-engine-from-file-m-c.patch
Of course not future-proof, but fixes the regression for the user.

That's also in Firefox code which we can't touch. Unless the Firefox folks can be convinced to remove it or change it to something that can be overridden.

We could indeed revive relevant parts of attachment 9030183 [details] [diff] [review]. Actually adding from a local xml file I can't think is very common. Adding from url would be much nicer, but it would require some strings...

https://bugzilla.mozilla.org supports this so can be used for testing

Pushed by mkmelin@iki.fi:
https://hg.mozilla.org/comm-central/rev/9006837ffea3
add search engine by url or discovery. r=henry

Probably best to let 10n work happen during the 94 cycle. Then I suppose we can take it for 91. The localization will be missing for some (but fall back to English). Anyway, on 91 it's completely broken so can't really get much worse...

Comment on attachment 9245090 [details]
Bug 1718411 - add search engine by url or discovery. r=henry

[Approval Request Comment]
Regression caused by (bug #): bug 1690750
User impact if declined: Add search engine doesn't work.
Testing completed (on c-c, etc.): c-c, soon beta
Risk to taking this patch (and alternatives if risky): it's not working. Alternatively just hide the "Add" button and don't allow the functionality - it's not much used I would think.

Comment on attachment 9245090 [details]
Bug 1718411 - add search engine by url or discovery. r=henry

[Triage Comment]
approved for esr91

Thunderbird 91.3.1:
https://hg.mozilla.org/releases/comm-esr91/rev/d7809d465b06