1 files changed, 18 insertions, 0 deletions
diff --git a/tests/mir-opt/const_prop/issue_66971.rs b/tests/mir-opt/const_prop/issue_66971.rs
new file mode 100644
index 000000000..6ca03438e
--- /dev/null
+++ b/tests/mir-opt/const_prop/issue_66971.rs
@@ -0,0 +1,18 @@
+// unit-test: ConstProp
+// compile-flags: -Z mir-opt-level=3
+
+// Due to a bug in propagating scalar pairs the assertion below used to fail. In the expected
+// outputs below, after ConstProp this is how _2 would look like with the bug:
+//
+//     _2 = (const Scalar(0x00) : (), const 0u8);
+//
+// Which has the wrong type.
+
+fn encode(this: ((), u8, u8)) {
+    assert!(this.2 == 0);
+}
+
+// EMIT_MIR issue_66971.main.ConstProp.diff
+fn main() {
+    encode(((), 0, 0));
+}