@Yann: Hi,where does something say 0.00 Megapixel somewhere? Please follow https://www.mediawiki.org/wiki/How_to_report_a_bug and use the bug report form for bug reports (it is linked at the top).

This reminded me a bit of T286273 but that one is about a PNG file instead.

In T297942#7577450, @Aklapper wrote:

@Yann: Hi,where does something say 0.00 Megapixel somewhere? Please follow https://www.mediawiki.org/wiki/How_to_report_a_bug and use the bug report form for bug reports (it is linked at the top).

I think this is done by a gadget, which calculate the size. Here 0 x 0 =0.

Hello,

I occur the same issue with this PDF : https://commons.wikimedia.org/wiki/File:L%E2%80%99Aclot.pdf, wich has a dimension 0 × 0 on Commons, but recognized correctly (1 237 × 1 750) on wa.wikisource https://wa.wikisource.org/wiki/File:L’Aclot.pdf

The strangest thing is that the version of December 9 at 9:06 pm was displayed with a dimension 0 × 0 (as summarized in the next version at 9:54 pm), but now this version is shown with the real dimension 1 237 × 1 750.

Older version of https://commons.wikimedia.org/wiki/File:The_Collected_Works_of_Mahatma_Gandhi,_vol._2.pdf
and https://commons.wikimedia.org/wiki/File:Gandhi_-_Dakshin_Afrika_Ke_Satyagraha_(Hindi).pdf

Another file: https://commons.wikimedia.org/wiki/File:%E0%A4%B8%E0%A4%AE%E0%A5%8D%E0%A4%AA%E0%A5%82%E0%A4%B0%E0%A5%8D%E0%A4%A3_%E0%A4%97%E0%A4%BE%E0%A4%81%E0%A4%A7%E0%A5%80_%E0%A4%B5%E0%A4%BE%E0%A4%82%E0%A4%97%E0%A5%8D%E0%A4%AE%E0%A4%AF_Sampurna_Gandhi,_vol._14.pdf

I went through all PDF and Djvu files on Commons and made a list of those which are valid, but are shown as 0x0 without thumbnails, the list is here: T301291

This still happens, see 2nd revision of https://commons.wikimedia.org/wiki/File:Robida_-_La_Guerre_au_vingti%C3%A8me_si%C3%A8cle,_bpt6k3120885.pdf

One more case https://commons.wikimedia.org/wiki/File:JohnAndPsalms.pdf

One more https://commons.wikimedia.org/wiki/File:Amulet_1833.pdf

One more https://commons.wikimedia.org/wiki/File:Singer-Siddur-1915-AI.pdf

One more https://commons.wikimedia.org/wiki/File:The_Century_Dictionary_and_Cyclopedia%2C_vol._2_(cu31924091890594).pdf 2nd version

I even got a "crash"

Request from 90.112.34.87 via cp6012 cp6012, Varnish XID 92742326
Error: 503, Backend fetch failed at Tue, 06 Jun 2023 10:59:01 GMT

Further issue is that it crashes this https://commons.wikimedia.org/w/index.php?title=Commons:MyGallery&withJS=MediaWiki:JSONListUploads.js&gUser=Yann

If code crashes then the code should be made more robust not to crash.

https://commons.wikimedia.org/wiki/File:First_book_of_the_Iliad;_Battle_of_the_frogs_and_mice;_Hymn_to_the_Delian_Apollo;_Bacchus,_or,_the_Rovers;_second_book_of_the_Iliad_(IA_firstbookofiliad00home).pdf

The problem seems to be not only PDF related. This djvu file shows the same effect:
https://commons.wikimedia.org/wiki/File:PL_JI_Kraszewski_Zygzaki.djvu
As a workaround, we uploaded the file directly to Wikisource:
https://pl.wikisource.org/wiki/Plik:PL_JI_Kraszewski_Zygzaki.djvu
It works. But should we stop using Commons?

Maybe RefreshImageMetadata.php on PL_JI_Kraszewski_Zygzaki.djvu would help?

In T297942#9644062, @Wargo wrote:

Maybe RefreshImageMetadata.php on PL_JI_Kraszewski_Zygzaki.djvu would help?

11:04:05 <@Urbanecm> RhinosF1: wargo: i tired, it did not help. however, manually constructing the URL where the thumbnail is supposed to be (https://upload.wikimedia.org/wikipedia/commons/thumb/archive/8/82/20230929224435%21PL_JI_Kraszewski_Zygzaki.djvu/page1-87px-PL_JI_Kraszewski_Zygzaki.djvu.jpg) appears to have worked

I think helped the first solution...