forgot to add this test

src/org/rascalmpl/library/lang/rascal/tests/concrete/Issue1913.rsc

@@ -0,0 +1,23 @@
+module lang::rascal::tests::concrete::Issue1913
+
+extend lang::std::Layout;
+import IO;
+
+syntax As = "begin" A* as "end";
+
+syntax A = "a" | "b";
+
+test bool issue1913() {
+    A* bs = (As)`begin b a b end`.as;
+
+    As prog = (As)`begin b a a end`;
+
+    prog = visit (prog) {
+        case (As)`begin <A* as1> b <A* as2> end` 
+            => (As)`begin <A* as1> <A* bs> <A* as2> end`
+    }
+
+    println(prog);
+    // don't loose a space
+    return "<prog>" == "begin b a b a a end";
+}