Have values in Section config trees refer to them in all components

Hard coding each and every component is not only boring but given that
everyone is free to add or use more we end up in situations in which apt
behaves differently for the same binary package just because metadata
said it is in different components (e.g. non-free vs. non-free-firmware).
It is also probably not what the casual user would expect.

So we instead treat a value without a component as if it applies for all
of them. The previous behaviour can be restored by prefixing the value
with "<undefined>/" as in the component is not defined.

In an ideal world we would probably use "*/foo" for the new default
instead of changing the behaviour for "foo", but it seems rather
unlikely that the old behaviour is actually desired. All existing values
were duplicated for all (previously) known components in Debian and
Ubuntu.

1 files changed, 23 insertions, 10 deletions

diff --git a/cmdline/apt-mark.cc b/cmdline/apt-mark.cc
index 5eaed2c71..46d3ca5b8 100644
--- a/cmdline/apt-mark.cc
+++ b/cmdline/apt-mark.cc
@@ -140,25 +140,38 @@ static bool DoMarkAuto(CommandLine &CmdL)
 }
 									/*}}}*/
 // helper for Install-Recommends-Sections and Never-MarkAuto-Sections	/*{{{*/
-static bool
-ConfigValueInSubTree(const char *SubTree, const char *needle)
+// FIXME: Copied verbatim from apt-pkg/depcache.cc
+static bool ConfigValueInSubTree(const char* SubTree, std::string_view const needle)
 {
-   // copied from depcache.cc
-   Configuration::Item const *Opts;
-   Opts = _config->Tree(SubTree);
-   if (Opts != 0 && Opts->Child != 0)
+   if (needle.empty())
+      return false;
+   Configuration::Item const *Opts = _config->Tree(SubTree);
+   if (Opts != nullptr && Opts->Child != nullptr)
    {
       Opts = Opts->Child;
-      for (; Opts != 0; Opts = Opts->Next)
+      for (; Opts != nullptr; Opts = Opts->Next)
       {
-	 if (Opts->Value.empty() == true)
+	 if (Opts->Value.empty())
 	    continue;
-	 if (strcmp(needle, Opts->Value.c_str()) == 0)
+	 if (needle == Opts->Value)
 	    return true;
       }
    }
    return false;
 }
+static bool SectionInSubTree(char const * const SubTree, std::string_view Needle)
+{
+   if (ConfigValueInSubTree(SubTree, Needle))
+      return true;
+   auto const sub = Needle.find('/');
+   if (sub == std::string_view::npos)
+   {
+      std::string special{"<undefined>/"};
+      special.append(Needle);
+      return ConfigValueInSubTree(SubTree, special);
+   }
+   return ConfigValueInSubTree(SubTree, Needle.substr(sub + 1));
+}
 									/*}}}*/
 /* DoMinimize - minimize manually installed	{{{*/
 /* Traverses dependencies of meta packages and marks them as manually
@@ -179,7 +192,7 @@ static bool DoMinimize(CommandLine &CmdL)
       auto ver = pkg.CurrentVer();
       return ver.end() == false && ((*DepCache)[pkg].Flags & pkgCache::Flag::Auto) == 0 &&
 	     ver->Section != 0 &&
-	     ConfigValueInSubTree("APT::Never-MarkAuto-Sections", ver.Section());
+	     SectionInSubTree("APT::Never-MarkAuto-Sections", ver.Section());
    };
 
    APT::PackageSet roots;