[Bug-wget] continuing download of unspecified-length files

[Ian Macky]

Hi, I have run into an unfortunate case with wget that I cannot find a
solution to (have read the man page several times, perhaps I missed it?):

1. I am on slow slow dialup (do not jeer, I am poor).  Downloads from
   the USPTO usually stall after 20 seconds, and will never restart.

2. Unfortunately, USPTO images are not provided with a length ("Length:
   unspecified [image/tiff]")

3. Without the length, wget -c will not continue a download, it just says
   the file is already fully retrieved.

What is needed is a way to continue downloads for unknown-length files.

I would suggest the correct behavior for -c in this case is for the current
size of the local file to be used as the starting point for the continued
download, just like usual, regardless of the fact that the remote size is
not known.

As it is, I cannot download the complete file with wget.  The connection
always times out, and wget refuses to continue the download.

Cheers,

--ian