workaround for a::"b"; "\n" may appear (quoted) in a name

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/RDeparse.java

@@ -275,7 +275,7 @@ public class RDeparse {
         private final int cutoff;
         private final boolean backtick;
         private int opts;
-        private final int nlines;
+        @SuppressWarnings("unused") private final int nlines;
 
         private int inCurly = 0;
         private int inList = 0;
@@ -322,7 +322,6 @@ public class RDeparse {
         }
 
         private DeparseVisitor append(String str) {
-            assert !str.contains("\n");
             sb.append(str);
             return this;
         }
@@ -549,7 +548,12 @@ public class RDeparse {
                         } else if (args.length == 1) {
                             append(args[0]).append(symbol).append("NULL");
                         } else {
-                            append(args[0]).append(symbol).append(args[1]);
+                            // FIXME use call syntax until parser fixed to accept literals
+                            if (args[1] instanceof RSyntaxConstant) {
+                                append('`').append(symbol).append('`').append('(').append(args[0]).append(", ").append(args[1]).append(')');
+                            } else {
+                                append(args[0]).append(symbol).append(args[1]);
+                            }
                         }
                         return null;
                     }