[[!comment format=mdwn
 username="joey"
 subject="""comment 1"""
 date="2018-11-12T19:27:00Z"
 content="""
Thing is, git-annex does not always know the size of an annexed object,
and also the same download function is used for downloading other things
than annexed objects, which git-annex never knows the size of.
So trying to paper over this problem by checking the size first wouldn't
fix all cases.

This is supposed to be handled by catching the 416 http error,
and checking that the Content-Range header looks like "bytes */$size"
which is at least one of the ways that http servers indicate the size of
the file.

But if a http server doesn't send such a Content-Range, 
it's not clear what to do. It could, I suppose, just give up
on resuming in that case, and re-download.

Anyway, please show the output of `git annex version`, because this could
potentially have to do with the version of http-client that git-annex was
built with.

Do you know of an url that still exists that can be used to reproduce this?
"""]]
