[vala/0.52] vala: Using SignalHandler.disconnect() is required for dynamic signals

[Rico Tzschichholz <ricotz src gnome org>]

commit 229816134d3e4885871debe7e89fcd42f8de86ce
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Nov 1 14:02:04 2021 +0100

    vala: Using SignalHandler.disconnect() is required for dynamic signals

 tests/Makefile.am                                     |  1 +
 tests/objects/signals-dynamic-invalid-disconnect.test | 15 +++++++++++++++
 vala/valamemberaccess.vala                            |  3 +++
 3 files changed, 19 insertions(+)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index f862af631..33cccdc7c 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -522,6 +522,7 @@ TESTS = \
        objects/signals-enum-marshal.vala \
        objects/signals-delegate.vala \
        objects/signals-delegate-parameter.vala \
+       objects/signals-dynamic-invalid-disconnect.test \
        objects/signals-dymanic-invalid-handler.test \
        objects/signals-dynamic-lambda-handler.test \
        objects/signals-error-marshal.vala \
diff --git a/tests/objects/signals-dynamic-invalid-disconnect.test 
b/tests/objects/signals-dynamic-invalid-disconnect.test
new file mode 100644
index 000000000..e1787ef24
--- /dev/null
+++ b/tests/objects/signals-dynamic-invalid-disconnect.test
@@ -0,0 +1,15 @@
+Invalid Code
+
+class Foo : Object {
+       public signal void sig ();
+}
+
+void sig_cb () {
+}
+
+void main () {
+       var real = new Foo ();
+       dynamic Object foo = real;
+
+       foo.sig.disconnect (sig_cb);
+}
diff --git a/vala/valamemberaccess.vala b/vala/valamemberaccess.vala
index a251ef118..b68676e44 100644
--- a/vala/valamemberaccess.vala
+++ b/vala/valamemberaccess.vala
@@ -490,6 +490,9 @@ public class Vala.MemberAccess : Expression {
                                                s.access = SymbolAccessibility.PUBLIC;
                                                dynamic_object_type.type_symbol.scope.add (null, s);
                                                symbol_reference = s;
+                                       } else if (ma.member_name == "disconnect") {
+                                               error = true;
+                                               Report.error (ma.source_reference, "Use 
SignalHandler.disconnect() to disconnect from dynamic signal");
                                        }
                                }
                                if (symbol_reference == null) {