When combined with the --continue option, should --timestamping send an
If-Unmodified-Since header?
Currently, if I partially download a file and then run `wget --debug
--continue --timestamping URL` I get:
---request begin---
GET [...] HTTP/1.1
If-Modified-Since: Tue, 13 Nov 2018 14:13:29 GMT
Range: bytes=1084899556-
[...]
---response begin---
HTTP/1.1 304 Not Modified
[...]
---response end---
304 Not Modified
File ‘[...]’ not modified on server. Omitting download.
and I'm left with the still-incomplete file 😞
If Wget instead sent If-Unmodified-Since, I'd expect it to resume
downloading:
---response begin---
HTTP/1.1 206 Partial Content
[...]
---response end---
206 Partial Content
Length: [...], [...] remaining
Saving to: ‘[...]’
If the file was already complete, I'd expect:
---response begin---
HTTP/1.1 416 Requested Range Not Satisfiable
[...]
---response end---
416 Requested Range Not Satisfiable
The file is already fully retrieved; nothing to do.
And if the file was out of date (complete or otherwise), I'd expect:
---response begin---
HTTP/1.1 412 Precondition Failed
[...]
---response end---
412 Precondition Failed
