Extend the default search pattern to support 'name:arch'

A search pattern with no explicit term, "s", is equivalent to
"?name(s)".  This changes modifies these semantics when the
pattern is arch-qualified, "name:arch" which is now equivalent
to "?exact-name(name) ?architecture(arch)".

These are the semantics used by apt-get and others which are
internally derived from pkgCache::FindPkg("name:arch").

On the command-line, it is possible to specify both an architecture
and an archive/version, as well as an override specifier:

 # aptitude install an:armel/sid tf:armel-

* src/generic/apt/matching/parse.cc:
  - extended semantics as per above.
* src/cmdline/cmdline_versions.cc:
  - modify argument processing to use the extended semantics.

2 files changed, 14 insertions, 15 deletions

diff --git a/src/cmdline/cmdline_versions.cc b/src/cmdline/cmdline_versions.cc
index 828e4239..8f57ff41 100644
--- a/src/cmdline/cmdline_versions.cc
+++ b/src/cmdline/cmdline_versions.cc
@@ -600,23 +600,16 @@ int cmdline_versions(int argc, char *argv[], const char *status_fname,
   for(int i = 1; i < argc; ++i)
     {
       const char * const arg = argv[i];
-      const bool treat_as_exact_name =
-        !aptitude::matching::is_pattern(arg);
 
-      if(treat_as_exact_name)
-        matchers.push_back(m::pattern::make_exact_name(arg));
-      else
-        {
-          cw::util::ref_ptr<m::pattern> m = m::parse(arg);
-          if(!m.valid())
-            {
-              _error->DumpErrors();
+      cw::util::ref_ptr<m::pattern> m = m::parse(arg);
+      if(!m.valid())
+	{
+	  _error->DumpErrors();
 
-              return -1;
-            }
+	  return -1;
+	}
 
-          matchers.push_back(m);
-        }
+      matchers.push_back(m);
     }
 
   return do_search_versions(matchers,
diff --git a/src/generic/apt/matching/parse.cc b/src/generic/apt/matching/parse.cc
index 98218bcb..f114cd81 100644
--- a/src/generic/apt/matching/parse.cc
+++ b/src/generic/apt/matching/parse.cc
@@ -1376,7 +1376,13 @@ ref_ptr<pattern> parse_atom(string::const_iterator &start,
 	{
 	  std::string s = parse_substr(start, end, terminators, true);
 
-	  return pattern::make_name(s);
+	  const size_t found = s.rfind(':');
+	  if(found == std::string::npos)
+	    return pattern::make_name(s);
+	  const std::string arch = s.substr(found + 1);
+	  const std::string name = s.substr(0, found);
+	  return pattern::make_and(pattern::make_exact_name(name),
+				   parse_architecture(arch));
 	}
     }