From ca35539f7cd7967bfd8518d0ad0b0015bdd40cfc Mon Sep 17 00:00:00 2001
From: Reinier Zwitserloot <reinier@zwitserloot.com>
Date: Tue, 21 Aug 2018 00:01:40 +0200
Subject: [fixes #1812] `@Singular` marked collections which nevertheless
 somehow ended up null would cause an NPE during `toBuilder()` invocations.

---
 src/core/lombok/javac/handlers/HandleBuilder.java | 28 ++++++++++++++++++-----
 1 file changed, 22 insertions(+), 6 deletions(-)

(limited to 'src/core/lombok/javac')

diff --git a/src/core/lombok/javac/handlers/HandleBuilder.java b/src/core/lombok/javac/handlers/HandleBuilder.java
index f04ea8b1..edf6f2ae 100644
--- a/src/core/lombok/javac/handlers/HandleBuilder.java
+++ b/src/core/lombok/javac/handlers/HandleBuilder.java
@@ -492,18 +492,34 @@ public class HandleBuilder extends JavacAnnotationHandler<Builder> {
 		JCExpression invoke = call;
 		for (BuilderFieldData bfd : builderFields) {
 			Name setterName = fluent ? bfd.name : type.toName(HandlerUtil.buildAccessorName("set", bfd.name.toString()));
-			JCExpression arg;
+			JCExpression[] tgt = new JCExpression[bfd.singularData == null ? 1 : 2];
 			if (bfd.obtainVia == null || !bfd.obtainVia.field().isEmpty()) {
-				arg = maker.Select(maker.Ident(type.toName("this")), bfd.obtainVia == null ? bfd.rawName : type.toName(bfd.obtainVia.field()));
+				for (int i = 0; i < tgt.length; i++) {
+					tgt[i] = maker.Select(maker.Ident(type.toName("this")), bfd.obtainVia == null ? bfd.rawName : type.toName(bfd.obtainVia.field()));
+				}
 			} else {
 				if (bfd.obtainVia.isStatic()) {
-					JCExpression c = maker.Select(maker.Ident(type.toName(type.getName())), type.toName(bfd.obtainVia.method()));
-					arg = maker.Apply(List.<JCExpression>nil(), c, List.<JCExpression>of(maker.Ident(type.toName("this"))));
+					for (int i = 0; i < tgt.length; i++) {
+						JCExpression c = maker.Select(maker.Ident(type.toName(type.getName())), type.toName(bfd.obtainVia.method()));
+						tgt[i] = maker.Apply(List.<JCExpression>nil(), c, List.<JCExpression>of(maker.Ident(type.toName("this"))));
+					}
 				} else {
-					JCExpression c = maker.Select(maker.Ident(type.toName("this")), type.toName(bfd.obtainVia.method()));
-					arg = maker.Apply(List.<JCExpression>nil(), c, List.<JCExpression>nil());
+					for (int i = 0; i < tgt.length; i++) {
+						JCExpression c = maker.Select(maker.Ident(type.toName("this")), type.toName(bfd.obtainVia.method()));
+						tgt[i] = maker.Apply(List.<JCExpression>nil(), c, List.<JCExpression>nil());
+					}
 				}
 			}
+			
+			JCExpression arg;
+			if (bfd.singularData == null) {
+				arg = tgt[0];
+			} else {
+				JCExpression eqNull = maker.Binary(CTC_EQUAL, tgt[0], maker.Literal(CTC_BOT, null));
+				JCExpression emptyList = maker.Apply(List.<JCExpression>nil(), chainDots(type, "java", "util", "Collections", "emptyList"), List.<JCExpression>nil());
+				arg = maker.Conditional(eqNull, emptyList, tgt[1]);
+			}
+			
 			invoke = maker.Apply(List.<JCExpression>nil(), maker.Select(invoke, setterName), List.of(arg));
 		}
 		JCStatement statement = maker.Return(invoke);
-- 
cgit