amended locale_declaration: avoid duplication of Local_Theory.target with global_morphism (cf. 57def0b39696) -- Haftmann-Wenzel Sandwich has 3 layers, not 4;

--- a/src/Pure/Isar/named_target.ML	Sat Mar 17 22:46:19 2012 +0100
+++ b/src/Pure/Isar/named_target.ML	Sat Mar 17 23:50:47 2012 +0100
@@ -55,12 +55,15 @@
     |> Local_Theory.target (add locale locale_decl)
   end;
 
-fun target_declaration (Target {target, ...}) {syntax, pervasive} decl =
-  if target = "" then Generic_Target.theory_declaration decl
+fun target_declaration (Target {target, ...}) {syntax, pervasive} decl lthy =
+  if target = "" then Generic_Target.theory_declaration decl lthy
   else
-    locale_declaration target syntax decl
-    #> pervasive ? Generic_Target.theory_declaration decl
-    #> not pervasive ? Context.proof_map (Morphism.form decl);
+    lthy
+    |> pervasive ? Local_Theory.background_theory
+        (Context.theory_map
+          (Morphism.form (Morphism.transform (Local_Theory.global_morphism lthy) decl)))
+    |> locale_declaration target syntax decl
+    |> Context.proof_map (Morphism.form decl);
 
 
 (* consts in locales *)