HHH-1904 Hash the natural id unique key names

Author: brmeyer

hibernate-core/src/main/java/org/hibernate/cfg/AnnotationBinder.java

@@ -155,6 +155,7 @@
 import org.hibernate.id.TableHiLoGenerator;
 import org.hibernate.id.enhanced.SequenceStyleGenerator;
 import org.hibernate.internal.CoreMessageLogger;
+import org.hibernate.internal.util.StringHelper;
 import org.hibernate.mapping.Any;
 import org.hibernate.mapping.Component;
 import org.hibernate.mapping.DependantValue;
@@ -2095,12 +2096,12 @@ else if ( !isId || !entityBinder.isIgnoreIdAnnotations() ) {
 		if ( naturalIdAnn != null ) {
 			if ( joinColumns != null ) {
 				for ( Ejb3Column column : joinColumns ) {
-					column.addUniqueKey( "_UniqueKey", inSecondPass );
+					column.addUniqueKey( StringHelper.randomFixedLengthHex("UK_"), inSecondPass );
 				}
 			}
 			else {
 				for ( Ejb3Column column : columns ) {
-					column.addUniqueKey( "_UniqueKey", inSecondPass );
+					column.addUniqueKey( StringHelper.randomFixedLengthHex("UK_"), inSecondPass );
 				}
 			}
 		}

hibernate-core/src/main/java/org/hibernate/cfg/HbmBinder.java

@@ -2248,7 +2248,7 @@ else if ( "filter".equals( name ) ) {
 			}
 			else if ( "natural-id".equals( name ) ) {
 				UniqueKey uk = new UniqueKey();
-				uk.setName("_UniqueKey");
+				uk.setName(StringHelper.randomFixedLengthHex("UK_"));
 				uk.setTable(table);
 				//by default, natural-ids are "immutable" (constant)
 				boolean mutableId = "true".equals( subnode.attributeValue("mutable") );