Fixes #2184: NPE on package-info.java without package declaration.

doc/changelog.markdown

@@ -11,6 +11,7 @@ Lombok Changelog
 * BUGFIX: Delombok would turn something like `List<byte[]>...` in a method parameter to `List<byte...>...` [Issue #2140](https://github.com/rzwitserloot/lombok/issues/2140)
 * BUGFIX: Javac would generate the wrong equals and hashCode if a type-use annotation was put on an array type field [Issue #2165](https://github.com/rzwitserloot/lombok/issues/2165)
 * BUGFIX: Eclipse 2019-06 + JDK-12 compatibility + an `@Singular` builder entry would produce a cascade of error dialogs. [Issue #2169](https://github.com/rzwitserloot/lombok/issues/2169)
+* BUGFIX: Javac would throw a NullPointerException if the package-info.java did not contain a package declaration. [Issue #2184](https://github.com/rzwitserloot/lombok/issues/2184)
 * IMPROBABLE BREAKING CHANGE: Stricter validation of configuration keys dealing with identifiers and types (`lombok.log.fieldName`, `lombok.fieldNameConstants.innerTypeName`, `lombok.copyableAnnotations`).
 * IMPROBABLE BREAKING CHANGE: The fields generated inside builders for fields with defaults (with `@Builder` on a class with fields marked `@Default`) now have `$value` as the name; direct manipulation of these fields is not advised because there is an associated `$set` variable that also needs to be taken into account. [Issue #2115](https://github.com/rzwitserloot/lombok/issues/2115)
 

src/core/lombok/javac/apt/LombokProcessor.java

@@ -389,7 +389,12 @@ public class LombokProcessor extends AbstractProcessor {
 	}
 	
 	private JCCompilationUnit toUnit(Element element) {
-		TreePath path = trees == null ? null : trees.getPath(element);
+		TreePath path = null;
+		if (trees != null) {
+			try {
+				path = trees.getPath(element);
+			} catch (NullPointerException ignore) {}
+		}
 		if (path == null) return null;
 		
 		return (JCCompilationUnit) path.getCompilationUnit();