vala: Infer target_type in coalescing expressions

Correctly handle reference tranfers of inner expressions.

Fixes https://gitlab.gnome.org/GNOME/vala/issues/892

2 files changed, 24 insertions, 0 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index a486591ec..2c66135bf 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -165,6 +165,7 @@ TESTS = \
 	control-flow/assigned-local-variable.vala \
 	control-flow/break.vala \
 	control-flow/break-invalid.test \
+	control-flow/coalesce-reference-transfer.vala \
 	control-flow/continue-invalid.test \
 	control-flow/double-catch.test \
 	control-flow/expressions-conditional.vala \
diff --git a/tests/control-flow/coalesce-reference-transfer.vala b/tests/control-flow/coalesce-reference-transfer.vala
new file mode 100644
index 000000000..4efbf3ed4
--- /dev/null
+++ b/tests/control-flow/coalesce-reference-transfer.vala
@@ -0,0 +1,23 @@
+[Compact]
+class Foo {
+	public int i;
+
+	public Foo (int i) {
+		this.i = i;
+	}
+}
+
+Foo? get_foo (int? i) {
+	return i != null ? new Foo (i) : null;
+}
+
+void main () {
+	{
+		Foo foo = get_foo (null) ?? get_foo (42);
+		assert (foo.i == 42);
+	}
+	{
+		Foo foo = get_foo (null) ?? (get_foo (null) ?? get_foo (42));
+		assert (foo.i == 42);
+	}
+}