Can you link to which image is being returned as webp?

In T209805#4756988, @Bawolff wrote:

Can you link to which image is being returned as webp?

I remembered the original URL of the image (in the screenshot) being:

https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/Iconsiam_at_Night.jpg/250px-Iconsiam_at_Night.jpg

But it changed to return conventional JPEG format shortly after I posted this report. (What a coincidence...)

However, there are multiple gallery images down below within that article which are still returned in WebP, at least in my browsing session; see below for URLs. (And before anyone asks, I confirm that file extensions in the URL really are what I wrote)

Part 1 (gallery screenshot):

• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )
• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )
• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )
• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )
• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )
• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )

Part 2 (gallery screenshot):

• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )
• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )

Icons are affected too (page screenshot):

• Screenshot ( WebP icon URL | Wikipedia info | Commons info )

Actually, most of the icons in File:* information pages' templates (on both English Wikipedia and Wikimedia Commons) are also affected.

Browser: Opera 11.64
U/A Identifier: Opera/9.80 (Windows NT 5.1; U; en) Presto/2.10.229 Version/11.64
System: Microsoft Windows XP Professional SP3

As usual, the browser is run without JavaScript enabled.

Please investigate and fix.
Browser: Opera 11.64

Note: That browser is >6years old and not supported as per https://www.mediawiki.org/wiki/Compatibility#Browser_support_matrix

Does the problem also happen with any other browsers? Which other browsers and browser versions have you tested?

In T209805#4757168, @Nvtj wrote:

• Screenshot ( WebP thumbnail URL | Wikipedia info | Commmons info )

Cannot reproduce, JPEG only:

$:acko\> wget -q "https://upload.wikimedia.org/wikipedia/commons/thumb/d/d3/%E0%B9%84%E0%B8%AD%E0%B8%84%E0%B8%AD%E0%B8%99%E0%B8%AA%E0%B8%A2%E0%B8%B2%E0%B8%A1_Grand_Openning_day_Iconsiam_of_Thailand_15_Copyrights_of_Trisorn_Triboon.jpg/120px-%E0%B9%84%E0%B8%AD%E0%B8%84%E0%B8%AD%E0%B8%99%E0%B8%AA%E0%B8%A2%E0%B8%B2%E0%B8%A1_Grand_Openning_day_Iconsiam_of_Thailand_15_Copyrights_of_Trisorn_Triboon.jpg"
$:acko\> file 120px-ไอคอนสยาม_Grand_Openning_day_Iconsiam_of_Thailand_15_Copyrights_of_Trisorn_Triboon.jpg 
120px-ไอคอนสยาม_Grand_Openning_day_Iconsiam_of_Thailand_15_Copyrights_of_Trisorn_Triboon.jpg: JPEG image data, Exif standard: [TIFF image data, big-endian, direntries=6, xresolution=86, yresolution=94, resolutionunit=2], baseline, precision 8, 120x80, frames 3

This is due to experiments with T27611: Serve optimized WebP thumbnails as alternative to JPEG, PNG

Opera 11.60 release in 2011-12-06 (.64 are just security updates). I guess in theory we could blacklist the old Opera UAs in the varnish config:
puppet/modules/thumbor/templates/varnish.vcl.erb

Opera webp support:
lossy profile: Opera 11.10+
lossy, lossless, and alpha: Opera 12

So it's supporting webp, but not all of webp.

Change 474693 had a related patch set uploaded (by Ema; owner: Ema):
[operations/puppet@production] Avoid serving WebP thumbnail variants to Opera

https://gerrit.wikimedia.org/r/474693

Note: The chromium/webkit versions of Opera after opera 15 use the OPR string to identify Opera. These browsers likely DO have proper webp support, as they are basically identically to Chrome.

https://dev.opera.com/blog/opera-user-agent-strings-opera-15-and-beyond/

@ema's patch seems to take this into account (consciously or not)

I guess this means that these older Opera versions send request headers stating that they accept webp when they're in fact incapable of rendering them?

@Gilles see my note in T209805#4758174 v11 probably supports some early versions of them, but not all.

Indeed. I've installed 11.64 and even the lossy ones we generate don't work. And it does advertise webp support in request headers:

I think it's fair to blacklist non-Blink Opera, even if some later ones (still pre-Blink) do support the images we generate. It must be a negligible portion of traffic and shrinking.

I've just verified the current stable Opera out of curiosity and it does (unsurprisingly) render our webps correctly.

Change 474693 merged by Ema:
[operations/puppet@production] Avoid serving WebP thumbnail variants to Opera

https://gerrit.wikimedia.org/r/474693