setup "Download Only" deltas against an existing installation (was emacs-w32 (64bit) displays generic tray icon)

[Shaddy Baddah <lithium-cygwin at shaddybaddah dot name>]

Hi,

On 16 Aug 2013 23:14+1000, Shaddy Baddah wrote:
> OK. It seems my mirror can be trusted. It seems setup cannot be trusted.
> That's a little unfair actually. More that... something I assumed about
> setup, but also based on the assumption thought would one day cause
> issue is the following.
>
> When you do a "Download Only", how does setup decide what the current
> version of your packages are? And if it finds an update path, will it
> automatically select the package for update?
>
> My understanding is it does look at your installation root, and will
> select existing packages for upgrade.
>
> However, as per http://cygwin.com/ml/cygwin-apps/2013-06/msg00042.html
> I wonder how it select the right installation root when there are
> multiple installs. I don't have multiple installs of 64 bit at the
> moment, but I do have a concurrent 32 bit. And in general, if I am
> right in saying it peeks into the targeted installation root for an
> existing "selection" of packages, there is no mechanism to point it
> at the right one when more than one exists.
>
> Anyway, this is turning into a discussion on setup. I'll take it to
> cygwin-apps if it is more appropriate. Actually, I will take it there
> as I have further comments.

OK. I think I've gotten myself in a muddle over this. And I apologise.

The various assumptions I've held onto on "Download Only" was possibly
based on a false nostalgia for the behaviour of setup against the
pre-fstab Cygwin.

It may not be true, but I thought that even in "Download Only" mode
setup would grab the installation root from the registry and use the
package list obtained from the installation root as the reference for
package selection.

However I realise now that if it did, it would have been a bumbling way
to do it even back then, *in the context* of how I install and run
Cygwin.

If I understand correctly, even back then, if a user was not privileged
to setup keys in HKLM, then on installation, the root would have been
put in HKCU. I perform my install under a separate user to my
personalised user, and that user is not in Administrators. So the root
would have been in HKCU back then too.

Subsequent attempts to "Download Only" as my personalised user, would
not have access to the other users registry keys anyway. So it would not
have been able to work out a correct installation root... unless setup
happened to fallback on the default c:/cygwin and found it in most
users cases.

In any case, the problem is fundamental. My personalised user isn't
performing installs, therefore "Download Only" would not be able to
"cross-reference" an installation root, if that function indeed exists.

Does it exist?

I know in the past that PTC has been suggested. I genuinely aim to
contribute when able. Everyone's busy so I won't whinge here, I'll
just say that at the moment it is tough for me to do so.

After being blind-sided by this gap in understanding, I'll be eyeing
any opportunity to work on a suitable improvement to setup.

--
Regards,
Shaddy