[#625] Instead of '31' as a prime number for hashCode(), use something else. 31, probably owing to its inclusion in Effective Java, is overused, as proven by Maaartinus in issue 625. Switching to 277 instead. Also, 1231/1237 pair used for booleans has been replaced by 2591/2609.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/core/lombok/javac/handlers/HandleEqualsAndHashCode.java b/src/core/lombok/javac/handlers/HandleEqualsAndHashCode.java
index f3641f7f..3f72f8a1 100644
--- a/src/core/lombok/javac/handlers/HandleEqualsAndHashCode.java
+++ b/src/core/lombok/javac/handlers/HandleEqualsAndHashCode.java
@@ -31,6 +31,7 @@ import java.util.Collections;
 import lombok.EqualsAndHashCode;
 import lombok.core.AST.Kind;
 import lombok.core.AnnotationValues;
+import lombok.core.handlers.HandlerUtil;
 import lombok.javac.Javac;
 import lombok.javac.JavacAnnotationHandler;
 import lombok.javac.JavacNode;
@@ -230,9 +231,9 @@ public class HandleEqualsAndHashCode extends JavacAnnotationHandler<EqualsAndHas
 		Name resultName = typeNode.toName(RESULT_NAME);
 		long finalFlag = JavacHandlerUtil.addFinalIfNeeded(0L, typeNode.getContext());
 		
-		/* final int PRIME = 31; */ {
+		/* final int PRIME = 277; */ {
 			if (!fields.isEmpty() || callSuper) {
-				statements.append(maker.VarDef(maker.Modifiers(finalFlag), primeName, maker.TypeIdent(CTC_INT), maker.Literal(31)));
+				statements.append(maker.VarDef(maker.Modifiers(finalFlag), primeName, maker.TypeIdent(CTC_INT), maker.Literal(HandlerUtil.PRIME_FOR_HASHCODE)));
 			}
 		}
 		
@@ -254,8 +255,9 @@ public class HandleEqualsAndHashCode extends JavacAnnotationHandler<EqualsAndHas
 			if (fType instanceof JCPrimitiveTypeTree) {
 				switch (((JCPrimitiveTypeTree)fType).getPrimitiveTypeKind()) {
 				case BOOLEAN:
-					/* this.fieldName ? 1231 : 1237 */
-					statements.append(createResultCalculation(typeNode, maker.Conditional(fieldAccessor, maker.Literal(1231), maker.Literal(1237))));
+					/* this.fieldName ? 2591 : 2609 */
+					statements.append(createResultCalculation(typeNode, maker.Conditional(fieldAccessor, 
+							maker.Literal(HandlerUtil.PRIME_FOR_FALSE), maker.Literal(HandlerUtil.PRIME_FOR_TRUE))));
 					break;
 				case LONG: {
 						Name dollarFieldName = dollar.append(((JCVariableDecl)fieldNode.get()).name);