From ba1231cd6770e668d6758567b3719d40808af806 Mon Sep 17 00:00:00 2001
From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Tue, 6 Apr 2021 13:00:16 +0200
Subject: [PATCH] codegen: Don't override valid target/destroy of previous
 lambda argument

This does not enable proper support for delegates sharing a data argument,
but allows this special case.

See https://gitlab.gnome.org/GNOME/vala/issues/59
---
 codegen/valaccodemethodcallmodule.vala     | 13 ++--
 tests/delegates/lambda-shared-closure.vala | 79 ++++++++++++++++++++++
 2 files changed, 88 insertions(+), 4 deletions(-)

diff --git a/codegen/valaccodemethodcallmodule.vala b/codegen/valaccodemethodcallmodule.vala
index d60fcf0a3..c1ef29677 100644
--- a/codegen/valaccodemethodcallmodule.vala
+++ b/codegen/valaccodemethodcallmodule.vala
@@ -445,10 +445,15 @@ public class Vala.CCodeMethodCallModule : CCodeAssignmentModule {
 									closure_new.add_argument (new CCodeCastExpression (delegate_target_destroy_notify, "GClosureNotify"));
 									cexpr = new CCodeConditionalExpression (new CCodeBinaryExpression (CCodeBinaryOperator.EQUALITY, cexpr, new CCodeConstant ("NULL")), new CCodeConstant ("NULL"), closure_new);
 								} else {
-									carg_map.set (get_param_pos (get_ccode_delegate_target_pos (param)), delegate_target);
-									if (deleg_type.is_disposable ()) {
-										assert (delegate_target_destroy_notify != null);
-										carg_map.set (get_param_pos (get_ccode_destroy_notify_pos (param)), delegate_target_destroy_notify);
+									// Override previously given target/destroy only if it was NULL
+									// TODO https://gitlab.gnome.org/GNOME/vala/issues/59
+									var node = carg_map.get (get_param_pos (get_ccode_delegate_target_pos (param)));
+									if (node == null || (node is CCodeConstant && ((CCodeConstant) node).name == "NULL")) {
+										carg_map.set (get_param_pos (get_ccode_delegate_target_pos (param)), delegate_target);
+										if (deleg_type.is_disposable ()) {
+											assert (delegate_target_destroy_notify != null);
+											carg_map.set (get_param_pos (get_ccode_destroy_notify_pos (param)), delegate_target_destroy_notify);
+										}
 									}
 								}
 							}
diff --git a/tests/delegates/lambda-shared-closure.vala b/tests/delegates/lambda-shared-closure.vala
index 028eca31a..08f694e6d 100644
--- a/tests/delegates/lambda-shared-closure.vala
+++ b/tests/delegates/lambda-shared-closure.vala
@@ -94,6 +94,80 @@ public class Foo : Object {
 	}
 }
 
+void call_shared ([CCode (delegate_target_cname = "user_data", delegate_target_pos = 2.9)] FooFunc a, [CCode (delegate_target_cname = "user_data", delegate_target_pos = 2.9)] FooFunc b) {
+	a ();
+	b ();
+}
+
+void call_shared_owned ([CCode (delegate_target_cname = "user_data", delegate_target_pos = 2.9)] owned FooFunc a, [CCode (delegate_target_cname = "user_data", delegate_target_pos = 2.9)] owned FooFunc b) {
+	a ();
+	b ();
+}
+
+void run_static_1 () {
+	var foo = new Foo ();
+
+	assert (foo.ref_count == 1);
+
+	call_shared (
+		() => {
+			assert (foo != null);
+		},
+		() => {
+		}
+	);
+
+	assert (foo.ref_count == 1);
+}
+
+void run_static_2 () {
+	var foo = new Foo ();
+
+	assert (foo.ref_count == 1);
+
+	call_shared (
+		() => {
+		},
+		() => {
+			assert (foo != null);
+		}
+	);
+
+	assert (foo.ref_count == 1);
+}
+
+void run_static_3 () {
+	var foo = new Foo ();
+
+	assert (foo.ref_count == 1);
+
+	call_shared_owned (
+		() => {
+			assert (foo != null);
+		},
+		() => {
+		}
+	);
+
+	assert (foo.ref_count == 1);
+}
+
+void run_static_4 () {
+	var foo = new Foo ();
+
+	assert (foo.ref_count == 1);
+
+	call_shared_owned (
+		() => {
+		},
+		() => {
+			assert (foo != null);
+		}
+	);
+
+	assert (foo.ref_count == 1);
+}
+
 void main () {
 	var foo = new Foo ();
 	assert (foo.ref_count == 1);
@@ -105,4 +179,9 @@ void main () {
 	assert (foo.ref_count == 1);
 	foo.run_4 ();
 	assert (foo.ref_count == 1);
+
+	run_static_1 ();
+	run_static_2 ();
+	run_static_3 ();
+	run_static_4 ();
 }
-- 
2.47.3