Fix coalescing operator semantics check.

The left operand was not put in any code block
before the check, thus it wasn't able to transform itself.

Fixes bug 691514.

3 files changed, 29 insertions, 1 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 6a36a4dd3..141b0484b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -65,6 +65,7 @@ TESTS = \
 	control-flow/sideeffects.vala \
 	control-flow/bug652549.vala \
 	control-flow/bug665904.vala \
+	control-flow/bug691514.vala	\
 	enums/enums.vala \
 	enums/bug673879.vala \
 	structs/structs.vala \
diff --git a/tests/control-flow/bug691514.vala b/tests/control-flow/bug691514.vala
new file mode 100644
index 000000000..661e73c04
--- /dev/null
+++ b/tests/control-flow/bug691514.vala
@@ -0,0 +1,23 @@
+public string[] test() throws Error {
+	return { null, "1" };
+}
+
+void main() {
+	string t = (true ? "1" : "2") ?? "3";
+	assert (t == "1");
+	
+	t = (false ? "1" : "2") ?? "3";
+	assert (t == "2");
+	
+	t = (true ? null : "2") ?? "3";
+	assert (t == "3");
+	
+	t = (false ? "1" : null) ?? "3";
+	assert (t == "3");
+	
+	t = test()[0] ?? "2";
+	assert (t == "2");
+	
+	t = test()[1] ?? "2";
+	assert (t == "1");
+}
diff --git a/vala/valabinaryexpression.vala b/vala/valabinaryexpression.vala
index 22c448384..2b7289c05 100644
--- a/vala/valabinaryexpression.vala
+++ b/vala/valabinaryexpression.vala
@@ -196,7 +196,6 @@ public class Vala.BinaryExpression : Expression {
 		if (operator == BinaryOperator.COALESCE) {
 			var local = new LocalVariable (null, get_temp_name (), left, source_reference);
 			var decl = new DeclarationStatement (local, source_reference);
-			decl.check (context);
 
 			var right_stmt = new ExpressionStatement (new Assignment (new MemberAccess.simple (local.name, right.source_reference), right, AssignmentOperator.SIMPLE, right.source_reference), right.source_reference);
 
@@ -211,6 +210,11 @@ public class Vala.BinaryExpression : Expression {
 			insert_statement (context.analyzer.insert_block, decl);
 			insert_statement (context.analyzer.insert_block, if_stmt);
 
+			if (!decl.check (context)) {
+				error = true;
+				return false;
+			}
+
 			if (!if_stmt.check (context)) {
 				error = true;
 				return false;