Fix for issues #869 and #1018

Generates the null check on the constructor parameter instead of the
instance field. Fix for issues #869 and #1018.

src/core/lombok/javac/handlers/HandleConstructor.java

@@ -291,7 +291,7 @@ public class HandleConstructor {
 				JCVariableDecl param = maker.VarDef(maker.Modifiers(flags, nonNulls.appendList(nullables)), fieldName, field.vartype, null);
 				params.append(param);
 				if (!nonNulls.isEmpty()) {
-					JCStatement nullCheck = generateNullCheck(maker, fieldNode, source);
+					JCStatement nullCheck = generateNullCheck(maker, fieldNode, param, source);
 					if (nullCheck != null) nullChecks.append(nullCheck);
 				}
 			}

src/core/lombok/javac/handlers/JavacHandlerUtil.java

@@ -1175,16 +1175,23 @@ public class JavacHandlerUtil {
 	}
 	
 	/**
-	 * Generates a new statement that checks if the given variable is null, and if so, throws a specified exception with the
+	 * Generates a new statement that checks if the given variable is null, and if so, throws a configured exception with the
 	 * variable name as message.
-	 * 
-	 * @param exName The name of the exception to throw; normally {@code java.lang.NullPointerException}.
 	 */
 	public static JCStatement generateNullCheck(JavacTreeMaker maker, JavacNode variable, JavacNode source) {
+		return generateNullCheck(maker, variable, (JCVariableDecl)variable.get(), source);
+	}
+
+	/**
+	 * Generates a new statement that checks if the given variable is null, and if so, throws a configured exception with the
+	 * variable name as message. This is a special case method reserved for use when the provided declaration differs from the
+	 * variable's declaration, i.e. in a constructor or setter where the local parameter is named the same but with the prefix
+	 * stripped as a result of @Accessors.prefix.
+	 */
+	public static JCStatement generateNullCheck(JavacTreeMaker maker, JavacNode variable, JCVariableDecl varDecl, JavacNode source) {
 		NullCheckExceptionType exceptionType = source.getAst().readConfiguration(ConfigurationKeys.NON_NULL_EXCEPTION_TYPE);
 		if (exceptionType == null) exceptionType = NullCheckExceptionType.NULL_POINTER_EXCEPTION;
 		
-		JCVariableDecl varDecl = (JCVariableDecl) variable.get();
 		if (isPrimitive(varDecl.vartype)) return null;
 		Name fieldName = varDecl.name;
 		JCExpression exType = genTypeRef(variable, exceptionType.getExceptionType());

test/transform/resource/after-delombok/ConstructorsWithAccessors.java

@@ -15,3 +15,38 @@ class ConstructorsWithAccessors {
 		this.__huh2 = _huh2;
 	}
 }
+
+class NonNullConstructorsWithAccessors {
+	@lombok.NonNull
+	Integer plower;
+	@lombok.NonNull
+	Integer pUpper;
+	@lombok.NonNull
+	Integer _huh;
+	@lombok.NonNull
+	Integer __huh2;
+
+	@java.beans.ConstructorProperties({"plower", "upper", "huh", "_huh2"})
+	@java.lang.SuppressWarnings("all")
+	@javax.annotation.Generated("lombok")
+	@lombok.Generated
+	public NonNullConstructorsWithAccessors(@lombok.NonNull final Integer plower, @lombok.NonNull final Integer upper, @lombok.NonNull final Integer huh, @lombok.NonNull final Integer _huh2) {
+		if (plower == null) {
+			throw new java.lang.NullPointerException("plower");
+		}
+		if (upper == null) {
+			throw new java.lang.NullPointerException("upper");
+		}
+		if (huh == null) {
+			throw new java.lang.NullPointerException("huh");
+		}
+		if (_huh2 == null) {
+			throw new java.lang.NullPointerException("_huh2");
+		}
+		this.plower = plower;
+		this.pUpper = upper;
+		this._huh = huh;
+		this.__huh2 = _huh2;
+	}
+}
+

test/transform/resource/before/ConstructorsWithAccessors.java

@@ -4,3 +4,11 @@
 	int _huh;
 	int __huh2;
 }
+
+@lombok.AllArgsConstructor @lombok.experimental.Accessors(prefix={"p", "_"}) class NonNullConstructorsWithAccessors {
+	@lombok.NonNull Integer plower;
+	@lombok.NonNull Integer pUpper;
+	@lombok.NonNull Integer _huh;
+	@lombok.NonNull Integer __huh2;
+}
+