Fixed app tests for state spaces

stack/prefixstore.go

@@ -26,6 +26,20 @@ func stateSpace(store state.KVStore, app string) state.KVStore {
 		store = pstore.store
 	}
 	// wrap it with the prefix
-	prefix := append([]byte(app), byte(0))
+	prefix := makePrefix(app)
 	return prefixStore{prefix, store}
 }
+
+func makePrefix(app string) []byte {
+	return append([]byte(app), byte(0))
+}
+
+// PrefixedKey gives us the absolute path to a key that is embedded in an
+// application-specific state-space.
+//
+// This is useful for tests or utilities that have access to the global
+// state to check individual app spaces.  Individual apps should not be able
+// to use this to read each other's space
+func PrefixedKey(app string, key []byte) []byte {
+	return append(makePrefix(app), key...)
+}