From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Fri, 4 Oct 2019 12:12:46 +0000 (+0200)
Subject: vala: Fix compatible/disposable check between structs and their subtypes
X-Git-Tag: 0.44.9~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0097345f417e0cec555f399f7183ec9c9ccd2655;p=thirdparty%2Fvala.git

vala: Fix compatible/disposable check between structs and their subtypes

This fixes memory leaks due to missing copy/destroy and improperly created
dup functions and allows direct assignment between structs and their
subtypes.

Fixes https://gitlab.gnome.org/GNOME/vala/issues/861
---

diff --git a/codegen/valaccodestructmodule.vala b/codegen/valaccodestructmodule.vala
index 048cbb790..83c1a67a3 100644
--- a/codegen/valaccodestructmodule.vala
+++ b/codegen/valaccodestructmodule.vala
@@ -303,7 +303,11 @@ public abstract class Vala.CCodeStructModule : CCodeBaseModule {
 		push_function (function);
 
 		var dest_struct = new GLibValue (get_data_type_for_symbol (st), new CCodeIdentifier ("(*dest)"), true);
-		foreach (var f in st.get_fields ()) {
+		unowned Struct sym = st;
+		while (sym.base_struct != null) {
+			sym = sym.base_struct;
+		}
+		foreach (var f in sym.get_fields ()) {
 			if (f.binding == MemberBinding.INSTANCE) {
 				var value = load_field (f, load_this_parameter ((TypeSymbol) st));
 				if ((!(f.variable_type is DelegateType) || get_ccode_delegate_target (f)) && requires_copy (f.variable_type))  {
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 4bb01b38f..959af3728 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -218,6 +218,7 @@ TESTS = \
 	enums/bug763831.vala \
 	enums/bug780050.vala \
 	structs/struct_only.vala \
+	structs/struct-base-types.vala \
 	structs/struct-empty-still.test \
 	structs/struct-no-gtype.vala \
 	structs/struct-static-field-initializer.vala \
diff --git a/tests/structs/struct-base-types.vala b/tests/structs/struct-base-types.vala
new file mode 100644
index 000000000..928f010bb
--- /dev/null
+++ b/tests/structs/struct-base-types.vala
@@ -0,0 +1,31 @@
+struct Foo {
+	public string s;
+}
+
+struct Bar : Foo {
+}
+
+void main () {
+	{
+		Bar bar = { "bar" };
+		Foo foo = bar;
+
+		assert (bar.s == "bar");
+		assert (bar.s == foo.s);
+
+		void* s1 = foo.s;
+		void* s2 = bar.s;
+		assert (s1 != s2);
+	}
+	{
+		Foo foo = { "foo" };
+		Bar bar = foo;
+
+		assert (foo.s == "foo");
+		assert (foo.s == bar.s);
+
+		void* s1 = foo.s;
+		void* s2 = bar.s;
+		assert (s1 != s2);
+	}
+}
diff --git a/vala/valadatatype.vala b/vala/valadatatype.vala
index 608178fde..a17066fcd 100644
--- a/vala/valadatatype.vala
+++ b/vala/valadatatype.vala
@@ -354,6 +354,11 @@ public abstract class Vala.DataType : CodeNode {
 					return true;
 				}
 			}
+
+			// Allow compatiblity of struct subtypes in both ways
+			if (expect_struct.is_subtype_of (expr_struct)) {
+				return true;
+			}
 		}
 
 		return false;
diff --git a/vala/valastruct.vala b/vala/valastruct.vala
index c96632805..e82f52329 100644
--- a/vala/valastruct.vala
+++ b/vala/valastruct.vala
@@ -447,6 +447,10 @@ public class Vala.Struct : TypeSymbol {
 			return true;
 		}
 
+		if (base_struct != null) {
+			return base_struct.is_disposable ();
+		}
+
 		foreach (Field f in fields) {
 			if (f.binding == MemberBinding.INSTANCE
 			    && f.get_attribute_bool ("CCode", "delegate_target", true)