Merge pull request diffblue#119 from trtikm/bugfix/add-token

Fix adding new taint tokens

Author: NathanJPhillips

src/goto-analyzer/taint_rules.cpp

@@ -114,8 +114,9 @@ boost::optional<taint_rulet::tainted_locationt> taint_rulet::tainted_locationt::
       << messaget::eom;
     return boost::none;
   }
-  taint_tokent token = taint_tokent::fresh();
-  tokens.left.insert({ taint_string, token });
+  // Try to add a new token, get the token added or already in the set
+  taint_tokent token =
+    tokens.left.insert({ taint_string, taint_tokent::fresh() }).first->second;
   return tainted_locationt(location, token, json["dereference"].is_true());
 }