[fixes #1997] try-with-resources where the thing you’re guarding is just a variable ref instead of a full decl (legal since JDK9) would break delombok

src/delombok/lombok/delombok/PrettyPrinter.java

@@ -1268,9 +1268,14 @@ public class PrettyPrinter extends JCTree.Visitor {
 			break;
 		case 1:
 			print("(");
-			JCVariableDecl decl = (JCVariableDecl) resources.get(0);
-			flagMod = -1L & ~FINAL;
-			printVarDefInline(decl);
+			JCTree resource = (JCTree) resources.get(0);
+			if (resource instanceof JCVariableDecl) {
+				JCVariableDecl decl = (JCVariableDecl) resource;
+				flagMod = -1L & ~FINAL;
+				printVarDefInline(decl);
+			} else {
+				print(resource);
+			}
 			print(") ");
 			break;
 		default:
@@ -1279,8 +1284,12 @@ public class PrettyPrinter extends JCTree.Visitor {
 			int c = 0;
 			for (Object i : resources) {
 				align();
-				flagMod = -1L & ~FINAL;
-				printVarDefInline((JCVariableDecl) i);
+				if (i instanceof JCVariableDecl) {
+					flagMod = -1L & ~FINAL;
+					printVarDefInline((JCVariableDecl) i);
+				} else {
+					print((JCTree) i);
+				}
 				if (++c == len) {
 					print(") ");
 				} else {

test/pretty/resource/after/tryWithResourcesVarRef.java

@@ -0,0 +1,9 @@
+import java.io.PrintWriter;
+public class TryWithResourcesVarRef {
+	{
+		PrintWriter pw = new PrintWriter(System.out);
+		try (pw) {
+			pw.println();
+		}
+	}
+}

test/pretty/resource/before/TryWithResourcesVarRef.java

@@ -0,0 +1,10 @@
+//version 9:
+import java.io.PrintWriter;
+public class TryWithResourcesVarRef {
+	{
+		PrintWriter pw = new PrintWriter(System.out);
+		try (pw) {
+			pw.println();
+		}
+	}
+}