[vala] codegen: Don't create temp var in transform_value if lvalue isn't allowed

[Luca Bruno <lucabru src gnome org>]

commit 4c0c5242cecef9d9e4f9c90cf934434416020524
Author: Luca Bruno <lucabru src gnome org>
Date:   Mon Oct 17 21:56:49 2011 +0200

    codegen: Don't create temp var in transform_value if lvalue isn't allowed
    
    Fixes bug 657378.

 codegen/valaccodebasemodule.vala |   19 ++++++++++++-------
 tests/Makefile.am                |    1 +
 tests/structs/bug657378.vala     |    7 +++++++
 3 files changed, 20 insertions(+), 7 deletions(-)
---
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index b4c5efd..df7af48 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -5102,8 +5102,6 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 	public TargetValue transform_value (TargetValue value, DataType? target_type, CodeNode node) {
 		var type = value.value_type;
 		var result = ((GLibValue) value).copy ();
-		result.value_type = target_type != null ? target_type : type;
-		result.value_type = result.value_type.copy ();
 		var requires_temp_value = false;
 
 		if (type.value_owned
@@ -5150,11 +5148,16 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			if (target_type is PointerType) {
 				// manual memory management for pointers
 			} else if (requires_destroy (type)) {
-				var temp_value = create_temp_value (type, false, node);
-				temp_ref_values.insert (0, ((GLibValue) temp_value).copy ());
-				store_value (temp_value, result);
-				result.cvalue = get_cvalue_ (temp_value);
-				requires_temp_value = false;
+				if (!is_lvalue_access_allowed (type)) {
+					// cannot assign to a temporary variable
+					temp_ref_values.insert (0, result.copy ());
+				} else {
+					var temp_value = create_temp_value (type, false, node);
+					temp_ref_values.insert (0, ((GLibValue) temp_value).copy ());
+					store_value (temp_value, result);
+					result.cvalue = get_cvalue_ (temp_value);
+					requires_temp_value = false;
+				}
 			}
 		}
 
@@ -5163,6 +5166,8 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			return result;
 		}
 
+		result.value_type = target_type.copy ();
+
 		if (gvalue_boxing) {
 			// implicit conversion to GValue
 			var temp_value = create_temp_value (target_type, true, node, true);
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 2a896bd..682b128 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -74,6 +74,7 @@ TESTS = \
 	structs/bug654646.vala \
 	structs/bug654753.vala \
 	structs/bug656693.vala \
+	structs/bug657378.vala \
 	structs/bug658048.vala \
 	structs/bug660426.vala \
 	structs/bug661945.vala \
diff --git a/tests/structs/bug657378.vala b/tests/structs/bug657378.vala
new file mode 100644
index 0000000..5ba8263
--- /dev/null
+++ b/tests/structs/bug657378.vala
@@ -0,0 +1,7 @@
+string foo (string format, ...) {
+	return format.vprintf (va_list ());
+}
+
+void main () {
+	assert (foo ("%s", "foo") == "foo");
+}