bug#51296: [PATCH] Add WebP format support

[Eli Zaretskii]

> Date: Wed, 20 Oct 2021 19:35:17 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 51296@debbugs.gnu.org
> 
> > +       '(libwebp "libwebp.dll")
> 
> This requires some Internet search, because DLLs on Windows usually
> have a numeric version indication in their names, as you see in the
> other cases.  In this case, the name produced by current versions of
> libwebp seems to be libwebp-7.dll, not just libwebp.dll.  But it's
> probably a good idea to leave libwebp.dll as a fallback.  So this
> should be
> 
>      '(libwebp "libwebp-7.dll" "libwebp.dll")

Btw, the Windows binaries available from the libwebp site don't seem
to include DLLs, only static libraries.  Caveat emptor!