1 files changed, 12 insertions, 0 deletions
diff --git a/tests/ui/macros/macro-metavar-expr-concat/empty-input.rs b/tests/ui/macros/macro-metavar-expr-concat/empty-input.rs
new file mode 100644
index 00000000000..caad63c5f6b
--- /dev/null
+++ b/tests/ui/macros/macro-metavar-expr-concat/empty-input.rs
@@ -0,0 +1,12 @@
+// Issue 50403
+// Ensure that `concat` can't create empty identifiers
+// FIXME(macro_metavar_expr_concat): this error message could be improved
+
+macro_rules! empty {
+    () => { ${concat()} } //~ ERROR expected identifier or string literal
+                          //~^ERROR expected expression
+}
+
+fn main() {
+    let x = empty!();
+}