[R-pkg-devel] check cross-references error: Non-file package-anchored link(s)

help("sp", "sp")[[1]]

Hi

I got caught by this new test this week in trying to push an updated release of the loon package to CRAN.

By following this thread, I corrected my cross-references to external packages but I got stymied by
the one I hoped to give to the  "sp" package for Spatial data

_________

Here is the history:

I tried
   \link[sp:sp]{sp}
which failed here:
Debian: <https://win-builder.r-project.org/incoming_pretest/loon_1.3.1_20200616_162128/Debian/00check.log>
Status: 1 WARNING


That was meant to correct an earlier attempt (it did for other links to "scales" for example) where I had tried
  \link[sp]{sp}
and  failed here:
Debian: <https://win-builder.r-project.org/incoming_pretest/loon_1.3.1_20200615_213749/Debian/00check.log>
Status: 1 WARNING


So to complete the possibilities as I understand them,  I just now tried
   \link{sp}
which, as might be expected, failed here:
Debian: <https://win-builder.r-project.org/incoming_pretest/loon_1.3.1_20200616_213921/Debian/00check.log>
Status: 1 WARNING
As expected, error here was different:  "Missing  link"  as opposed to "Non-file package-anchored link"

_________


I am not sure whether I have missed a subtlety in WRE or that the peculiar circumstance
where the package, the topic, and the file name are all identical (sp) is some weird boundary case.

Without further advice, I think I am just going to remove the link to "sp".
It really is just a courtesy link to the package description for "sp".

Thanks in advance for your thoughts.

Wayne




?-----Original Message-----
From: R-package-devel <r-package-devel-bounces at r-project.org> on behalf of Georgi Boshnakov <georgi.boshnakov at manchester.ac.uk>
Date: Tuesday, June 16, 2020 at 9:27 AM
To: G?bor Cs?rdi <csardi.gabor at gmail.com>, Duncan Murdoch <murdoch.duncan at gmail.com>
Cc: List r-package-devel <r-package-devel at r-project.org>
Subject: Re: [R-pkg-devel] check cross-references error: Non-file package-anchored link(s)

    I think that the current behaviour is documented in WRE:

    "...There are two other forms of optional argument specified as \link[pkg]{foo} and
    \link[pkg:bar]{foo} to link to the package pkg, to files foo.html and bar.html respectively.
    These are rarely needed, perhaps to refer to not-yet-installed packages (but there the HTML
    help system will resolve the link at run time) or in the normally undesirable event that more
    than one package offers help on a topic7 (in which case the present package has precedence so
    this is only needed to refer to other packages). They are currently only used in HTML help
    (and ignored for hyperlinks in LATEX conversions of help pages), and link to the file rather
    than the topic (since there is no way to know which topics are in which files in an uninstalled
    package) ...   Because they have been frequently misused, the HTML help system looks for topic foo in package pkg
    if it does not find file foo.html."

    Unless I am missing something, it seems that it would be relatively painless to reverse the logic of the current behaviour of the help system,
    i.e. to start looking first for the topic and then for a file.

    Georgi Boshnakov

    -----Original Message-----
    From: R-package-devel <r-package-devel-bounces at r-project.org> On Behalf Of G?bor Cs?rdi
    Sent: 16 June 2020 13:44
    To: Duncan Murdoch <murdoch.duncan at gmail.com>
    Cc: List r-package-devel <r-package-devel at r-project.org>
    Subject: Re: [R-pkg-devel] check cross-references error: Non-file package-anchored link(s)

    On Mon, Jun 15, 2020 at 5:30 PM Duncan Murdoch <murdoch.duncan at gmail.com> wrote:

    >
    > On 15/06/2020 12:05 p.m., Martin Maechler wrote:

    > >>>>>> Duncan Murdoch   on Sun, 14 Jun 2020 07:28:03 -0400 writes:

    > >

    > >      > I agree with almost everything you wrote, except one thing:  this isn't
    > >      > newly enforced, it has been enforced since the help system began.  What
    > >      > I think is new is that there are now tests for it.  Previously those
    > >      > links just wouldn't work.

    > >

    > >      > Duncan Murdoch

    > >
    > > Yes, to all... including Duncan's agreement with G?bor.
    > >
    > > Also, Duncan M earlier did mention that he had wanted to
    > > *change* the link-to-file behavior for these cases (when he wrote
    > > most of the Rd2html source code) but somehow did not get it.

    >
    > Actually, I don't think I pushed for this change at the time (or at
    > least I didn't push much).  I just wish now that I had, because I
    > think it will be harder to do it now than it would have been then.
    >
    > Duncan

    I am not entirely sure, but maybe just documenting the current behaviour and undoing 78674 could work. With some tweaks? E.g.

    * updating R-exts to say that \link[pkg:topic]{text} will link to `topic.html` in `pkg` first (for historical reasons), and falls back to searching for `topic` in `pkg` at render time.
    * updating Rd2HTML to look for the topic and use it in the link, instead of throwing a warning, in it cannot find `topic.html`
    * removing the `R CMD check` warning for non-file links, that was added in 78674 :)

    Is there anything else?

    Gabor

    [...]