[pca] Can pca check two different local sources?

[Martin Paul]

Craig S. Bell wrote:
>   Martin, regarding pca-dev and multi-element xrefurl: Should "pca -x"
> always try the proxy when I include proxy-specific options such as
> "-F" and/or "--nocache"?

No, it will always try the sources strictly in the order as specified in 
"xrefurl". It will use the first xref it finds, not looking at the timestamp (so 
it will e.g. not find the newest xref file in all URLs).

Also be aware that the "nocache" option does not influence the pca proxy. It's 
for normal web proxies, instructing them to ignore any possible cached copies. 
You get the same effect (for xref, patches and READMEs) with a PCA proxy when 
using the "force" option. Now that I'm writing this, I start to think whether it 
makes sense to combine these options into one, even if they are doing different 
things behind the scenes.

>   My client xrefurl lists file:/ first, then the proxy URL.  The proxy
> uses that same file:/ path for patchdir and xrefdir.

Ok, in that case the clients will always get the copy in the file:/ URL, which 
might get older and older, until either it is updated manually by you or 
somebody gets the xref through the proxy, making it update the copy in xrefdir.

>   When I'm not using "-F" or "--nocache", I still want the ability to
> use an arbitrary xref file without checking the timestamp, i.e. a
> "golden" xref that I have set aside.

I think it's a simple decision about whether to use a "golden" xref (set xrefurl 
to file:/) or whether to use the most recent file (set xrefurl to pca proxy).

Using the "force" option for downloading the xref file is usually not necessary, 
as pca (in "normal" and in proxy mode) will check for a new file whenever it 
hasn't done so in the last three hours.

Hope that's OK for your local setup,

Martin.