Windows show-stopper: File.unlink doesn't work like it does on POSIX systems

[GregMefford]

On Windows, File#unlink does not delete the file like it does on POSIX, so ZipFile fails to create the file, trying to validate the (empty) tempfile. File.close! closes and then unlinks it, which is fine since we aren't writing to it directly anyway.
On a more abstract level, I'm not sure why we are creating a Tempfile to begin with. Couldn't we just go ahead and write to the file we're trying to create, or at least to a "filename.temp.jar" in the same directory instead of in the temp directory?

[nicksieger]

Thanks. Yeah we could write to the current directory, but all we need is a single empty jar file. I wrote it to use tempfile so the current directory wouldn't get cluttered.

[enebo]

def empty_jar_path
Tempfile.open(["empty", "jar"]) { |t| return t.path }
end

This seems mildly more safe since it guarantees tempfile will not leave around an open file in case of weird behavior with underlying filesystem. I say mildly, because any weird artifact of underlying filesystem might leak through our impl of Tempfile (JRuby has native impl and does not use Delegate ruby-based one).