From: Princeton Ferro <princetonferro@gmail.com>
Date: Fri, 17 Apr 2020 06:45:12 +0000 (-0400)
Subject: vala: Ensure non-empty argument list for "disconnect" before accessing it
X-Git-Tag: 0.49.1~164
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f7b5187218dcf51a9ec182114fb104aef97289d;p=thirdparty%2Fvala.git

vala: Ensure non-empty argument list for "disconnect" before accessing it

Avoids an internal assertion on accessing an empty collection.
---

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0593bef60..3476db7b1 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -900,6 +900,7 @@ TESTS = \
 	semantic/signal-detail-invalid.test \
 	semantic/signal-detail-non-string.test \
 	semantic/struct-derived.test \
+	semantic/signal-disconnect-empty-invalid.test \
 	semantic/signal-disconnect-invalid.test \
 	semantic/signal-return-valist.test \
 	semantic/struct-field-initializer.test \
diff --git a/tests/semantic/signal-disconnect-empty-invalid.test b/tests/semantic/signal-disconnect-empty-invalid.test
new file mode 100644
index 000000000..2830ed975
--- /dev/null
+++ b/tests/semantic/signal-disconnect-empty-invalid.test
@@ -0,0 +1,10 @@
+Invalid Code
+
+class Foo : Object {
+	public signal void bar ();
+}
+
+void main () {
+	var foo = new Foo ();
+	foo.bar.disconnect ();
+}
diff --git a/vala/valamethodcall.vala b/vala/valamethodcall.vala
index 98a7a878e..3573113c4 100644
--- a/vala/valamethodcall.vala
+++ b/vala/valamethodcall.vala
@@ -536,8 +536,7 @@ public class Vala.MethodCall : Expression {
 
 			unowned Signal? sig = m.parent_symbol as Signal;
 			if (sig != null && m.name == "disconnect") {
-				var param = argument_list[0];
-				if (param is LambdaExpression) {
+				if (!argument_list.is_empty && argument_list[0] is LambdaExpression) {
 					error = true;
 					Report.error (source_reference, "Cannot disconnect lambda expression from signal");
 					return false;