[vala/0.46] vala: Inherit CCode.returns_floating_reference attribute from base method

[Rico Tzschichholz <ricotz src gnome org>]

commit e0a9a4420324f18e9964372f6695eac920031dc9
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Aug 4 09:02:25 2020 +0200

    vala: Inherit CCode.returns_floating_reference attribute from base method
    
    Regression of 49a6d475052ec476140c545a26ac8d5abe35c849
    
    Fixes https://gitlab.gnome.org/GNOME/vala/issues/1053

 tests/Makefile.am                                  |  1 +
 tests/semantic/floating-reference-base-method.vala | 49 ++++++++++++++++++++++
 vala/valamethod.vala                               |  9 ++++
 3 files changed, 59 insertions(+)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index c5e400dd4..0e35fd799 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -800,6 +800,7 @@ TESTS = \
        semantic/field-valist.test \
        semantic/field-void.test \
        semantic/floating-reference.vala \
+       semantic/floating-reference-base-method.vala \
        semantic/floating-reference-error.vala \
        semantic/foreach-iterator-args.test \
        semantic/foreach-iterator-element-owned.test \
diff --git a/tests/semantic/floating-reference-base-method.vala 
b/tests/semantic/floating-reference-base-method.vala
new file mode 100644
index 000000000..d5151efa8
--- /dev/null
+++ b/tests/semantic/floating-reference-base-method.vala
@@ -0,0 +1,49 @@
+interface IFoo {
+       [CCode (returns_floating_reference = true)]
+       public abstract InitiallyUnowned? foo ();
+}
+
+interface IBar {
+       [CCode (returns_floating_reference = true)]
+       public abstract InitiallyUnowned? bar ();
+}
+
+class Foo : IFoo, IBar {
+       [CCode (returns_floating_reference = true)]
+       public InitiallyUnowned? foo () {
+               return null;
+       }
+
+       public InitiallyUnowned? bar () {
+               return null;
+       }
+
+       [CCode (returns_floating_reference = true)]
+       public virtual InitiallyUnowned? faz () {
+               return null;
+       }
+
+       [CCode (returns_floating_reference = true)]
+       public virtual InitiallyUnowned? baz () {
+               return null;
+       }
+}
+
+class Manam : Foo {
+       [CCode (returns_floating_reference = true)]
+       public override InitiallyUnowned? faz () {
+               return null;
+       }
+
+       public override InitiallyUnowned? baz () {
+               return null;
+       }
+}
+
+void main () {
+       var manam = new Manam ();
+       manam.foo ();
+       manam.bar ();
+       manam.faz ();
+       manam.baz ();
+}
diff --git a/vala/valamethod.vala b/vala/valamethod.vala
index 1084746cb..b2b2012aa 100644
--- a/vala/valamethod.vala
+++ b/vala/valamethod.vala
@@ -364,6 +364,13 @@ public class Vala.Method : Subroutine, Callable {
                        }
                }
 
+               var return_type = this.return_type.copy ();
+               if (has_attribute_argument ("CCode", "returns_floating_reference")) {
+                       return_type.floating_reference = returns_floating_reference;
+               } else {
+                       return_type.floating_reference = base_method.returns_floating_reference;
+               }
+
                var actual_base_type = base_method.return_type.get_actual_type (object_type, 
method_type_args, node_reference);
                if (!return_type.equals (actual_base_type)) {
                        invalid_match = "Base method expected return type `%s', but `%s' was provided".printf 
(actual_base_type.to_prototype_string (), return_type.to_prototype_string ());
@@ -625,6 +632,7 @@ public class Vala.Method : Subroutine, Callable {
 
                                _base_method = base_method;
                                copy_attribute_double (base_method, "CCode", "instance_pos");
+                               copy_attribute_bool (base_method, "CCode", "returns_floating_reference");
                                return;
                        }
                }
@@ -684,6 +692,7 @@ public class Vala.Method : Subroutine, Callable {
                if (base_match != null) {
                        _base_interface_method = base_match;
                        copy_attribute_double (base_match, "CCode", "instance_pos");
+                       copy_attribute_bool (base_match, "CCode", "returns_floating_reference");
                        return;
                } else if (!hides && invalid_base_match != null) {
                        error = true;