From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Thu, 26 Sep 2019 09:08:31 +0000 (+0200)
Subject: vala: Allow to override virtual interface implementations
X-Git-Tag: 0.44.9~25
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=02d15a060d40e54228aca2449ba8e233408ca3af;p=thirdparty%2Fvala.git

vala: Allow to override virtual interface implementations

Fixes https://gitlab.gnome.org/GNOME/vala/issues/852
---

diff --git a/codegen/valaccodemethodmodule.vala b/codegen/valaccodemethodmodule.vala
index e30e14647..2546b4d8a 100644
--- a/codegen/valaccodemethodmodule.vala
+++ b/codegen/valaccodemethodmodule.vala
@@ -541,7 +541,7 @@ public abstract class Vala.CCodeMethodModule : CCodeStructModule {
 					if (m.overrides || (m.base_interface_method != null && !m.is_abstract && !m.is_virtual)) {
 						Method base_method;
 						ReferenceType base_expression_type;
-						if (m.overrides) {
+						if (m.overrides && m.base_method != null) {
 							base_method = m.base_method;
 							base_expression_type = new ObjectType ((Class) base_method.parent_symbol);
 						} else {
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 4f88ae151..b8fd4d20e 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -311,6 +311,7 @@ TESTS = \
 	objects/interface_only.vala \
 	objects/interfaces.vala \
 	objects/interface-generics.vala \
+	objects/interface-virtual-override.vala \
 	objects/methods.vala \
 	objects/paramspec.vala \
 	objects/plugin-module-init.vala \
diff --git a/tests/objects/interface-virtual-override.vala b/tests/objects/interface-virtual-override.vala
new file mode 100644
index 000000000..62fcb6597
--- /dev/null
+++ b/tests/objects/interface-virtual-override.vala
@@ -0,0 +1,16 @@
+interface IFoo : Object {
+	public virtual int foo () {
+		assert_not_reached ();
+	}
+}
+
+class Bar : Object, IFoo {
+	public override int foo () {
+		return 42;
+	}
+}
+
+void main () {
+	var bar = new Bar ();
+	assert (bar.foo () == 42);
+}
diff --git a/vala/valamethod.vala b/vala/valamethod.vala
index 03653fee9..c8d691c7c 100644
--- a/vala/valamethod.vala
+++ b/vala/valamethod.vala
@@ -877,7 +877,7 @@ public class Vala.Method : Subroutine, Callable {
 				Report.error (source_reference, "A struct member `%s' cannot be marked as override, virtual, or abstract".printf (get_full_name ()));
 				return false;
 			}
-		} else if (overrides && base_method == null) {
+		} else if (overrides && base_method == null && base_interface_method == null) {
 			Report.error (source_reference, "`%s': no suitable method found to override".printf (get_full_name ()));
 		} else if ((is_abstract || is_virtual || overrides) && access == SymbolAccessibility.PRIVATE) {
 			error = true;