Downloadiong and file dates

Downloadiong and file dates

[Lennart Borgman]

When downloading a file from Launchpad's repository's web interface
the downloaded file does not get the right modified/creation time.

The headers in a buffer downloaded with url-retrieve-synchronously says

HTTP/1.1 200 OK
Date: Mon, 04 Jan 2010 01:50:08 GMT
Server: PasteWSGIServer/0.5 Python/2.5.2
Content-Type: application/octet-stream
Content-Length: 13071
Content-Disposition: attachment; filename*=utf-8''foldit.el
Via: 1.1 bazaar.launchpad.net
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Content-Language: el


The "Date" is obviously now when I tested. That seems correct. However
it would be good to have the modification time for the file too. There
is a "Last-Modified" header that perhaps could be used for this. Would
that be correct use for that header?

And how does url-copy-file handle this? This function has an argument
named `keep-time' but it is not easy to see where and how it is used.
From the doc string it looks liike it preserves the date of an old
local file.

Does url-copy-file take care of "Last-Modified" if present? Should it?

Re: Downloadiong and file dates

[James Cloos]

>>>>> "Lennart" == Lennart Borgman <lennart.borgman@gmail.com> writes:

Lennart> There is a "Last-Modified" header that perhaps could be used
Lennart> for this. Would that be correct use for that header?

Yes; that is exactly what most (every?) http client uses to set the
mtime on downloaded files.

Lennart> Does url-copy-file take care of "Last-Modified" if present? Should it?

It ought to.

-JimC
-- 
James Cloos <cloos@jhcloos.com>         OpenPGP: 1024D/ED7DAEA6

Re: Downloadiong and file dates

[Lennart Borgman]

On Mon, Jan 4, 2010 at 11:20 PM, James Cloos <cloos@jhcloos.com> wrote:
>>>>>> "Lennart" == Lennart Borgman <lennart.borgman@gmail.com> writes:
>
> Lennart> There is a "Last-Modified" header that perhaps could be used
> Lennart> for this. Would that be correct use for that header?
>
> Yes; that is exactly what most (every?) http client uses to set the
> mtime on downloaded files.


Thanks James.


> Lennart> Does url-copy-file take care of "Last-Modified" if present? Should it?
>
> It ought to.


A simple test of file download from EmacsWiki which uses
"Last-Modified" for files shows that it does not.

So there are two bugs here, one at Launchpad (does not send
"Last-Modified") and one in Emacs (does not use "Last-Modified"). I
will try to report them.


> -JimC
> --
> James Cloos <cloos@jhcloos.com>         OpenPGP: 1024D/ED7DAEA6
>

Re: Downloadiong and file dates

[Lennart Borgman]

On Mon, Jan 4, 2010 at 11:38 PM, Lennart Borgman
<lennart.borgman@gmail.com> wrote:
> On Mon, Jan 4, 2010 at 11:20 PM, James Cloos <cloos@jhcloos.com> wrote:
>>>>>>> "Lennart" == Lennart Borgman <lennart.borgman@gmail.com> writes:
>>
>> Lennart> There is a "Last-Modified" header that perhaps could be used
>> Lennart> for this. Would that be correct use for that header?
>>
>> Yes; that is exactly what most (every?) http client uses to set the
>> mtime on downloaded files.
>
>
> Thanks James.
>
>
>> Lennart> Does url-copy-file take care of "Last-Modified" if present? Should it?
>>
>> It ought to.
>
>
> A simple test of file download from EmacsWiki which uses
> "Last-Modified" for files shows that it does not.
>
> So there are two bugs here, one at Launchpad (does not send
> "Last-Modified") and one in Emacs (does not use "Last-Modified"). I
> will try to report them.


The Launchpad bug report is here:

    https://bugs.launchpad.net/launchpad/+bug/503144


>> -JimC
>> --
>> James Cloos <cloos@jhcloos.com>         OpenPGP: 1024D/ED7DAEA6
>>
>