3 files changed, 34 insertions, 20 deletions
diff --git a/mod/build-config-module.cxx b/mod/build-config-module.cxx
index 97c9f9e..1f4ad42 100644
--- a/mod/build-config-module.cxx
+++ b/mod/build-config-module.cxx
@@ -148,26 +148,35 @@ namespace brep
   }
 
   bool build_config_module::
-  belongs (const build_target_config& cfg, const char* cls) const
+  derived (const string& c, const char* bc) const
   {
+    if (c == bc)
+      return true;
+
+    // Go through base classes.
+    //
     const map<string, string>& im (target_conf_->class_inheritance_map);
 
-    for (const string& c: cfg.classes)
+    for (auto i (im.find (c)); i != im.end (); )
     {
-      if (c == cls)
+      const string& base (i->second);
+
+      if (base == bc)
         return true;
 
-      // Go through base classes.
-      //
-      for (auto i (im.find (c)); i != im.end (); )
-      {
-        const string& base (i->second);
+      i = im.find (base);
+    }
 
-        if (base == cls)
-          return true;
+    return false;
+  }
 
-        i = im.find (base);
-      }
+  bool build_config_module::
+  belongs (const build_target_config& cfg, const char* cls) const
+  {
+    for (const string& c: cfg.classes)
+    {
+      if (derived (c, cls))
+        return true;
     }
 
     return false;
diff --git a/mod/build-config-module.hxx b/mod/build-config-module.hxx
index c1630b0..bbbe952 100644
--- a/mod/build-config-module.hxx
+++ b/mod/build-config-module.hxx
@@ -54,15 +54,20 @@ namespace brep
                             default_all_ucs);
     }
 
+    // Return true if a class is derived from the base class, recursively.
+    //
+    bool
+    derived (const string&, const char* base_class) const;
+
     // Check if the configuration belongs to the specified class.
     //
     bool
     belongs (const build_target_config&, const char*) const;
 
     bool
-    belongs (const build_target_config& cfg, const string& cls) const
+    belongs (const build_target_config& cfg, const string& classes) const
     {
-      return belongs (cfg, cls.c_str ());
+      return belongs (cfg, classes.c_str ());
     }
 
     // Target/configuration/toolchain combination that, in particular, can be
diff --git a/mod/mod-build-configs.cxx b/mod/mod-build-configs.cxx
index 0ac4615..ce79edb 100644
--- a/mod/mod-build-configs.cxx
+++ b/mod/mod-build-configs.cxx
@@ -125,19 +125,19 @@ handle (request& rq, response& rs)
     s << DIV(ID="filter-heading") << "Build Configuration Classes" << ~DIV
       << P(ID="filter");
 
+    bool printed (false);
     for (auto b (cls.begin ()), i (b), e (cls.end ()); i != e; ++i)
     {
-      // Skip the 'hidden' class.
+      // Skip the hidden classes.
       //
       const string& c (*i);
 
-      if (c != "hidden")
+      if (!derived (c, "hidden"))
       {
-        // Note that here we rely on the fact that the first class in the list
-        // can never be 'hidden' (is always 'all').
-        //
-        if (i != b)
+        if (printed)
           s << ' ';
+        else
+          printed = true;
 
         print_class_name (c, c == selected_class);