BUG: fix the default "Unspecified" component when only the generic (i.e. not

RUNTIME, ARCHIVE, LIBRARY, etc.) arguments are given.

If the component of a part of a target is queried, return the specific one,
if a specific one hasn't been set, return the generic one, if that hasn't
been set, return "Unspecified".

Alex

Source/cmInstallCommandArguments.cxx

@@ -40,9 +40,7 @@ cmInstallCommandArguments::cmInstallCommandArguments()
 ,NamelinkOnly  (&Parser, "NAMELINK_ONLY" , &ArgumentGroup)
 ,NamelinkSkip  (&Parser, "NAMELINK_SKIP" , &ArgumentGroup)
 ,GenericArguments(0)
-{
-  this->Component.SetDefaultString("Unspecified");
-}
+{}
 
 const std::string& cmInstallCommandArguments::GetDestination() const
 {
@@ -67,7 +65,9 @@ const std::string& cmInstallCommandArguments::GetComponent() const
     {
     return this->GenericArguments->GetComponent();
     }
-  return this->EmptyString;
+
+  static std::string unspecifiedComponent = "Unspecified";
+  return unspecifiedComponent;
 }
 
 const std::string& cmInstallCommandArguments::GetRename() const