Reserve variable names/components that start with underscore to build2 core

1 files changed, 3 insertions, 3 deletions

diff --git a/libbuild2/variable.cxx b/libbuild2/variable.cxx
index 1855f3e..d84945f 100644
--- a/libbuild2/variable.cxx
+++ b/libbuild2/variable.cxx
@@ -1553,7 +1553,7 @@ namespace build2
     }
   }
 
-  variable& variable_pool::
+  pair<variable&, bool> variable_pool::
   insert (string n,
           const build2::value_type* t,
           const variable_visibility* v,
@@ -1619,7 +1619,7 @@ namespace build2
       update (var, pt, pv, po); // Not changing the key.
     }
 
-    return var;
+    return pair<variable&, bool> (var, r.second);
   }
 
   const variable& variable_pool::
@@ -1631,7 +1631,7 @@ namespace build2
                          var.type,
                          &var.visibility,
                          nullptr /* override */,
-                         false   /* pattern  */));
+                         false   /* pattern  */).first);
 
     assert (a.overrides == nullptr);