codegen: Don't leak memory of already assigned out-parameter on error

Fixes https://gitlab.gnome.org/GNOME/vala/issues/1123

3 files changed, 21 insertions, 0 deletions

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index b1f7e6869..b7db31835 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -3972,6 +3972,17 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		}
 	}
 
+	public void append_out_param_free (Method? m) {
+		if (m == null) {
+			return;
+		}
+		foreach (Parameter param in m.get_parameters ()) {
+			if (param.direction == ParameterDirection.OUT && param.variable_type.is_disposable ()) {
+				ccode.add_expression (destroy_parameter (param));
+			}
+		}
+	}
+
 	public bool variable_accessible_in_finally (LocalVariable local) {
 		if (current_try == null) {
 			return false;
diff --git a/codegen/valagasyncmodule.vala b/codegen/valagasyncmodule.vala
index f39f86c6e..c9946599f 100644
--- a/codegen/valagasyncmodule.vala
+++ b/codegen/valagasyncmodule.vala
@@ -743,8 +743,12 @@ public class Vala.GAsyncModule : GtkModule {
 		set_error.add_argument (error_expr);
 		ccode.add_expression (set_error);
 
+		// free local variables
 		append_local_free (current_symbol);
 
+		// free possibly already assigned out-parameter
+		append_out_param_free (current_method);
+
 		// We already returned the error above, we must not return anything else here.
 		var unref = new CCodeFunctionCall (new CCodeIdentifier ("g_object_unref"));
 		unref.add_argument (async_result_expr);
diff --git a/codegen/valagerrormodule.vala b/codegen/valagerrormodule.vala
index fedc424ae..d724c3c3a 100644
--- a/codegen/valagerrormodule.vala
+++ b/codegen/valagerrormodule.vala
@@ -104,6 +104,9 @@ public class Vala.GErrorModule : CCodeDelegateModule {
 		// free local variables
 		append_local_free (current_symbol);
 
+		// free possibly already assigned out-parameter
+		append_out_param_free (current_method);
+
 		if (current_method is CreationMethod && current_method.parent_symbol is Class) {
 			var cl = (Class) current_method.parent_symbol;
 			ccode.add_expression (destroy_value (new GLibValue (new ObjectType (cl), new CCodeIdentifier ("self"), true)));
@@ -123,6 +126,9 @@ public class Vala.GErrorModule : CCodeDelegateModule {
 			append_local_free (current_symbol);
 		}
 
+		// free possibly already assigned out-parameter
+		append_out_param_free (current_method);
+
 		cfile.add_include ("glib.h");
 
 		var ccritical = new CCodeFunctionCall (new CCodeIdentifier ("g_critical"));