Julia: Base.download() no longer unzips .gz

[RankWinner]

On Windows 'Base.download()' would unzip '.gz' files automatically when saving (which I don't believe was a documented feature), in 0.7.0-DEV this doesn't happen anymore.

Seems to be caused by #25477 as the old ccall to 'URLDownloadToFileW' appears to be what used to do the unzipping .gz for the download.

Since unzipping was never documented I doubt it was originally an intended feature, if so then I'll close the issue.

[StefanKarpinski]

That does seem like it was a rather surprising an unintentional feature. I would very much not expect the download function to do anything but, you know, download something.

[nalimilan]

I'm surprised you say the old version unzipped files, as the docs for URLDownloadToFileW don't mention this at all, and that's not what I observe on Windows 10 (for example with https://github.com/JuliaLang/julia/releases/download/v0.6.2/julia-0.6.2.tar.gz). Can you show a reproducer?

[RankWinner]

Yeah, thought as much, I'll close the issue. Should help if anybody else runs into the same thing.

[RankWinner]

@nalimilan Sorry didn't see your comment, here you go: https://gist.github.com/RankWinner/cc99137c1f7f9df428dcb6e69646f259

In 0.6.2 the file is downloaded and (seemingly?) unzipped, can be opened by a text editor/read by readdlm.

In 0.7.0 the file is downloaded as (I assume) a .gz, it's only 718 KB vs. the 4,684 KB file you get in 0.6.2, opening it in a text editor shows 1f8b 0800 174f 855a 0203 ec5d f953 e348 which I guess is the compressed .gz data. In the notebook I use 7zip included in Julia to uncompress it before reading it with readdlm.

[nalimilan]

Funny, I can reproduce with your example. It probably have to do with the way the HTTP server describes the file: indeed it uses Content-Encoding: x-gzip and Content-Type: text/plain.

Anyway, the 0.7 behavior is much saner.

[ihnorton]

the docs for URLDownloadToFileW don't mention this at all

I think this behavior is: https://msdn.microsoft.com/en-us/library/windows/desktop/aa383955(v=vs.85).aspx

(all these years I've been installing 7-zip to deal with .gz files on Windows...)