Fix semantics for coalesce operator when target_type is null.

Fixes bug 639482

3 files changed, 16 insertions, 3 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 85a92139b..5d89abfe7 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -63,6 +63,7 @@ TESTS = \
 	control-flow/foreach.vala \
 	control-flow/switch.vala \
 	control-flow/sideeffects.vala \
+	control-flow/bug639482.vala \
 	control-flow/bug652549.vala \
 	control-flow/bug665904.vala \
 	control-flow/bug691514.vala	\
diff --git a/tests/control-flow/bug639482.vala b/tests/control-flow/bug639482.vala
new file mode 100644
index 000000000..27a8e20ba
--- /dev/null
+++ b/tests/control-flow/bug639482.vala
@@ -0,0 +1,4 @@
+void main () {
+	string empty = null;
+	assert ((false ? "A" : (empty ?? "B")) == "B");
+}
diff --git a/vala/valabinaryexpression.vala b/vala/valabinaryexpression.vala
index 2b7289c05..19766e12f 100644
--- a/vala/valabinaryexpression.vala
+++ b/vala/valabinaryexpression.vala
@@ -221,10 +221,18 @@ public class Vala.BinaryExpression : Expression {
 			}
 
 			var ma = new MemberAccess.simple (local.name, source_reference);
-			ma.target_type = target_type;
-			ma.check (context);
+			Expression replace = ma;
 
-			parent_node.replace_expression (this, ma);
+			if (target_type == null) {
+				replace = new ReferenceTransferExpression (replace, source_reference);
+				replace.target_type = local.variable_type.copy ();
+				replace.target_type.value_owned = true;
+			} else {
+				replace.target_type = target_type.copy ();
+			}
+			replace.check (context);
+
+			parent_node.replace_expression (this, replace);
 
 			return true;
 		}