From 171b0e3a3b6f5bde0489c0e12c679fcefdeca54f Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Thu, 2 Sep 2021 11:31:25 +0200
Subject: Don't consider aliasing in variable override lookup

---
 libbuild2/scope.cxx    | 6 +++++-
 libbuild2/variable.cxx | 5 +++--
 libbuild2/variable.hxx | 8 +++++---
 3 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/libbuild2/scope.cxx b/libbuild2/scope.cxx
index ad01aa7..39aba8f 100644
--- a/libbuild2/scope.cxx
+++ b/libbuild2/scope.cxx
@@ -319,8 +319,12 @@ namespace build2
         return lookup_type ();
 
       // Note: using the original as storage variable.
+      // Note: have to suppress aliases since used for something else.
       //
-      return lookup_type (s->vars.lookup (*o).first, &var, &s->vars);
+      return lookup_type (
+        s->vars.lookup (*o, true /* typed */, false /* aliased */).first,
+        &var,
+        &s->vars);
     };
 
     // Return true if a value is from this scope (either target type/pattern-
diff --git a/libbuild2/variable.cxx b/libbuild2/variable.cxx
index d84945f..0cf6528 100644
--- a/libbuild2/variable.cxx
+++ b/libbuild2/variable.cxx
@@ -1721,7 +1721,7 @@ namespace build2
   const variable_map empty_variable_map (nullptr /* context */);
 
   auto variable_map::
-  lookup (const variable& var, bool typed) const ->
+  lookup (const variable& var, bool typed, bool aliased) const ->
     pair<const value_data*, const variable&>
   {
     const variable* v (&var);
@@ -1739,7 +1739,8 @@ namespace build2
         break;
       }
 
-      v = v->aliases;
+      if (aliased)
+        v = v->aliases;
 
     } while (v != &var && v != nullptr);
 
diff --git a/libbuild2/variable.hxx b/libbuild2/variable.hxx
index fc446bc..df0cb77 100644
--- a/libbuild2/variable.hxx
+++ b/libbuild2/variable.hxx
@@ -1555,11 +1555,13 @@ namespace build2
       return var != nullptr ? operator[] (*var) : lookup_type ();
     }
 
-    // If typed is false, leave the value untyped even if the variable is.
-    // The second half of the pair is the storage variable.
+    // If typed is false, leave the value untyped even if the variable is. If
+    // aliased is false, then don't consider aliases (used by the variable
+    // override machinery where the aliases chain is repurrposed for something
+    // else). The second half of the pair is the storage variable.
     //
     pair<const value_data*, const variable&>
-    lookup (const variable&, bool typed = true) const;
+    lookup (const variable&, bool typed = true, bool aliased = true) const;
 
     pair<value_data*, const variable&>
     lookup_to_modify (const variable&, bool typed = true);
-- 
cgit v1.1