HHH-19784 Fix for package-private fields in same hierarchy using different class loaders

Author: mbellade

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/internal/bytebuddy/EnhancerImpl.java

@@ -823,8 +823,23 @@ String getDescriptor() {
 return fieldDescription.getDescriptor();
 }
 
-boolean isVisibleTo(TypeDescription typeDescription) {
-return fieldDescription.isVisibleTo( typeDescription );
+boolean isVisibleTo(TypeDescription type) {
+final var declaringType = fieldDescription.getDeclaringType().asErasure();
+if ( declaringType.isVisibleTo( type ) ) {
+if ( fieldDescription.isPublic() || type.equals( declaringType ) ) {
+return true;
+}
+else if ( fieldDescription.isProtected() ) {
+return declaringType.isAssignableFrom( type );
+}
+else if ( fieldDescription.isPrivate() ) {
+return type.isNestMateOf( declaringType );
+}
+// We explicitly consider package-private fields as not visible, as the classes
+// might have the same package name but be loaded by different class loaders.
+// (see https://hibernate.atlassian.net/browse/HHH-19784)
+}
+return false;
 }
 
 FieldDescription getFieldDescription() {