fetchzip downloads the file from specified URL, renames it to basename
of that url, and then relies on unzip to do the unpacking.
The first consequence is that this requires URL to end with proper
extension—otherwise it will fail to unpack. This is not always the
case and input-fonts workarounds this by adding “&.zip” query
parameter (which is obviously a hack and is not guaranteed to work
with every URL).
The second consequence is that basename of the url must be a valid
filename. I’ve tried to build a custom configuration of input-fonts
and I get an error from mv that the filename is too long:
> trying https://input.djr.com/build/?fontSelection=fourStyleFamily®ular=InputMonoNarrow-Regular&italic=InputMonoNarrow-Italic&bold=InputMonoNarrow-Bold&boldItalic=InputMonoNarrow-BoldItalic&a=0&g=0&i=topserif&l=serifs_round&zero=0&asterisk=height&braces=straight&preset=default&line-height=1.2&accept=I+do&email=&.zip
> % Total % Received % Xferd Average Speed Time Time Time Current
> Dload Upload Total Spent Left Speed
> 100 406k 100 406k 0 0 230k 0 0:00:01 0:00:01 --:--:-- 230k
> mv: failed to access '/build/?fontSelection=fourStyleFamily®ular=InputMonoNarrow-Regular&italic=InputMonoNarrow-Italic&bold=InputMonoNarrow-Bold&boldItalic=InputMonoNarrow-BoldItalic&a=0&g=0&i=topserif&l=serifs_round&zero=0&asterisk=height&braces=straight&preset=default&line-height=1.2&accept=I+do&email=&.zip': File name too long
We could use “name” parameter as the filename (that’s how it is used
in fetchurl). However, the previous attempt to do
so (fc01353703) was
reverted (24b5eb61eb) because of the
introduced regression—many fetchzip invocations use names without
extension (also the default name is just “source”).
This commit adds an optional “extension” parameter. If it is set,
fetchzip renames the downloaded file to “download.${extension}”
effectively solving both problems above without introducing a massive
regression.
This is a no-op for all existing packages.
Tested by updating my NixOS setup + the extra inputs-fonts
configuration mentioned above + tons of unstable emacs packages after
a nix-collect-garbage (3Gb downloaded) with this patch applied.
1893e2be4d