remote-time doesn't cope with pre-epoch times

[edent]

Not sure if this is a bug, or something which should be clarified in the documentation.

Files with a Last-Modified time before the UNIX Epoch are saved with the current time, regardless of whether the filesystem supports older dates.

For example:

curl -ORv beatles.example/john-lennon

> GET /john-lennon HTTP/1.1
> Host: beatles.example
> User-Agent: curl/7.81.0
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Connection: Keep-Alive
< Keep-Alive: timeout=5, max=100
< Last-Modified: Wed, 09 Oct 1940 16:45:49 +0100

Will be saved with today's date.

Using wget will save with the original filedate all the way back to whatever my filesystem supports.

I think this is caused by

curl/src/tool_filetime.c

Lines 89 to 91 in f08ecdc

	void setfiletime(curl_off_t filetime, const char *filename)
	{
	if(filetime >= 0) {

It doesn't explicitly set the file's timestamp for negative values.

I'm not well versed enough in C to know if this is a limitation of the standard library or a design decision.

• Is it worth me sending a PR to clarify this at https://curl.se/docs/manpage.html#-R ?
• Should the code be updated to support older timestamps?

[splitbrain]

Sounds like a bug (or missing feature) to me. I think it's worth opening an issue.

[bagder]

See #18443

[bagder]

Fix coming in 8.16.0