Fix a bug on default initialization of interface typed value. (#4249)

* Fix a bug on default initialization of interface typed value.

* Fix.

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/language-feature/interfaces/zero-init-interface.slang b/tests/language-feature/interfaces/zero-init-interface.slang
new file mode 100644
index 000000000..ee38f4d83
--- /dev/null
+++ b/tests/language-feature/interfaces/zero-init-interface.slang
@@ -0,0 +1,32 @@
+// Test that we can zero-init a struct with interface typed member.
+
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=BUFFER): -shaderobj
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+interface IFoo
+{
+    int method();
+}
+
+//TEST_INPUT: type_conformance Impl1:IFoo = 0
+struct Impl1 : IFoo
+{
+    int data;
+    int method() { return data + 1; }
+}
+
+struct MyType
+{
+    IFoo foo;
+}
+
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+    MyType t = {};
+    // BUFFER: 1
+    outputBuffer[0] = t.foo.method();
+}