The idea behind this would be to have one ikiwiki behave as a dynamic private wiki in a specified area
and a more static publiczone wiki. Actually private wiki page can be addressed via a *pagespec*. 

What is ready /can be done:

* We already can more or less do this for example with [[httpauth|/plugins/httpauth/]], *.htaccess* files and a proper *httpauth_pagespec*
yet at the cost of maintaining two different user/pass logbase (native ikiwiki signin)
* Furthermore we can [[lockedit|plugins/lockedit/]] some pagespecs, ie in the public zone.

What is problematic is when you link a public page in a private page : 
a backlink will be generated from the public page to the private page.

As I noticed in [[per_page_ACLs]] in the end users through backlink 
navigation will frequently hit HTTP/401 deterring browsing as well as for the admin at false-positive logwatching.

One can radically [[disable backlinks feature|todo/allow_disabling_backlinks]] but then no more neat backlink navigation that
is really good to have in both area.

I think of just preventing this backlink leak in that case would be sufficient via i.e a *privatebacklinks* config and
a below patch.

Comments are welcome.

[[mathdesc]]


<pre>
diff --git a/IkiWiki.pm b/IkiWiki.pm
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -294,6 +294,14 @@ sub getsetup () {
                safe => 1,
                rebuild => 1,
        },
+       privatebacklinks => {
+               type => "pagespec",
+               example => "",
+               description => "PageSpec controlling which backlinks are private (ie users/*)",
+               link => "ikiwiki/PageSpec",
+               safe => 1,
+               rebuild => 1,
+       },
        hardlink => {
                type => "boolean",
                default => 0,
diff --git a/IkiWiki/Render.pm b/IkiWiki/Render.pm
--- a/IkiWiki/Render.pm
+++ b/IkiWiki/Render.pm
@@ -52,7 +52,8 @@ sub backlinks ($) {
                        $p_trimmed=~s/^\Q$dir\E// &&
                        $page_trimmed=~s/^\Q$dir\E//;
                               
-               push @links, { url => $href, page => pagetitle($p_trimmed) };
+               push @links, { url => $href, page => pagetitle($p_trimmed) }
+               unless defined $config{privatebacklinks} && length $config{privatebacklinks} && pagespec_match($p, $config{privatebacklinks}) && !pagespec_match($page, $config{privatebacklinks}) ;
        }
        return @links;
 }

</pre>