if matching a ref, return a tree type

A match will turn a ref into a tree. Need to return a tree type.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/synthesis.cc b/src/synthesis.cc
index 1fb8c17a..64178cae 100644
--- a/src/synthesis.cc
+++ b/src/synthesis.cc
@@ -1171,6 +1171,7 @@ UniqueType *LangVarRef::evaluateCall( Compiler *pd, CodeVect &code, CallArgVect
 	return lookup.uniqueType;
 }
 
+/* Can match on a tree or a ref. A tree always comes back. */
 UniqueType *LangTerm::evaluateMatch( Compiler *pd, CodeVect &code ) const
 {
 	/* Add the vars bound by the pattern into the local scope. */
@@ -1205,6 +1206,10 @@ UniqueType *LangTerm::evaluateMatch( Compiler *pd, CodeVect &code ) const
 		}
 	}
 
+	/* The process of matching turns refs into trees. */
+	if ( ut->typeId == TYPE_REF )
+		ut = pd->findUniqueType( TYPE_TREE, ut->langEl );
+
 	return ut;
 }