Once added in Firefox

Thanks for reporting. What are the steps to "add it in Firefox" exactly, so someone else could try to reproduce the issue?

Here is how to do it: https://support.mozilla.org/en-US/kb/add-or-remove-search-engine-firefox#w_add-a-search-engine

The icons are shown correctly before we add the search engines. But once added, they change to a generic icon.

I see the default icon for wikinews but I can't seem to add the wikipedia search.

I see the default icon for wikinews but I can't seem to add the wikipedia search.

That's probably because it's included by default. You can go to a different wikipedia language to add it or remove it and add it back.

Okay... How do I get the English one back?

This part feels like a bug in Firefox.

You should be able to add it back by following the procedure in the link I've posted.
If not, at which point doesn't it work?

I suppose it's irrelevant to this bug but going to frwiki and adding the search there only gives you frwiki searching, you still can't add enwiki searching back.

Anyway I wonder if this might be https://bugzilla.mozilla.org/show_bug.cgi?id=361923
I downloaded both, and...
-rw-rw-r-- 1 alex alex 15086 Mar 14 18:08 wikinews.ico
-rw-rw-r-- 1 alex alex 2734 Mar 14 18:08 wikipedia.ico

In T136286#2330763, @Krenair wrote:

Anyway I wonder if this might be https://bugzilla.mozilla.org/show_bug.cgi?id=361923
I downloaded both, and...
-rw-rw-r-- 1 alex alex 15086 Mar 14 18:08 wikinews.ico
-rw-rw-r-- 1 alex alex 2734 Mar 14 18:08 wikipedia.ico

The one I tested had 2,07 kB, so perhaps not...

Might be relevant to the recent HTTPS switchover - all engines I've checked have HTTP link to icon (or data URI)

@Krenair pls provide the link to upstream report, thx

In T136286#2330875, @Danny_B wrote:

Might be relevant to the recent HTTPS switchover

It seems unlikely. That was over a year ago. Would no-one have noticed for that long?

In T136286#2330876, @Danny_B wrote:

@Krenair pls provide the link to upstream report, thx

I posted it above

In T136286#2330884, @Krenair wrote:

In T136286#2330876, @Danny_B wrote:

@Krenair pls provide the link to upstream report, thx

I posted it above

Therefore not - as I mentioned below it, I tested with small icon and it didn't work either, thus such report isn't obviously the relevant one.

In T136286#2330878, @Jdforrester-WMF wrote:

In T136286#2330875, @Danny_B wrote:

Might be relevant to the recent HTTPS switchover

It seems unlikely. That was over a year ago. Would no-one have noticed for that long?

It depends... see T134869: Secure connection failed when attempting to send POST request using HTTP/2 (if connection has been idle for a certain time) (I forgot to add HTTP/2)

@The_RedBurn : Please provide browser and OS version, thanks.

In T136286#2330836, @Danny_B wrote:

In T136286#2330763, @Krenair wrote:

Anyway I wonder if this might be https://bugzilla.mozilla.org/show_bug.cgi?id=361923
I downloaded both, and...
-rw-rw-r-- 1 alex alex 15086 Mar 14 18:08 wikinews.ico
-rw-rw-r-- 1 alex alex 2734 Mar 14 18:08 wikipedia.ico

The one I tested had 2,07 kB, so perhaps not...

I think you mean this one: https://en.wiktionary.org/static/favicon/wiktionary/en.ico
Firefox says it's 2,07 KB, but if you save it to your disk, you'll see the real size is 14,7 KB. The size reported by Firefox isn't the full size (it's a multipart file).

An easy workaround for this Firefox bug would be to remove the 48x48 part for the Opensearch specific icon.
Currently, the Opensearch plugin uses the site favicon.

Reproduced with Firefox 46.0.1 on Windows 7.

In T136286#2331710, @The_RedBurn wrote:

In T136286#2330836, @Danny_B wrote:

The one I tested had 2,07 kB, so perhaps not...

I think you mean this one: https://en.wiktionary.org/static/favicon/wiktionary/en.ico
Firefox says it's 2,07 KB, but if you save it to your disk, you'll see the real size is 14,7 KB. The size reported by Firefox isn't the full size (it's a multipart file).

Aha! Therefore it will be the issue @Krenair linked (sorry, Alex ;-))

An easy workaround for this Firefox bug would be to remove the 48x48 part for the Opensearch specific icon.
Currently, the Opensearch plugin uses the site favicon.

That would require to have a pair of (fav)icons for each project (which is not only each family, since some projects have even their own, typically Wiktionaries...)

@Danny_B: I don't see anything in the MediaWiki-extensions-OpenSearchXml code base related to this task. Could you elaborate why you added that project?

Relict of switching between tabs. Originally intedned that one, but after finding out details about it, I switched to MediaWiki-General. IDK why it didn't save properly. Fixed. Thanks.

Firefox rejecting externally loaded favicons larger than 10 kB seems to be deliberate on Firefox’s part (https://developer.mozilla.org/en-US/Add-ons/Creating_OpenSearch_plugins_for_Firefox). Many OpenSearch plugins available from the Firefox add-ons website solve the problem by encoding the icon in Base64 format within the file.