refactor & bug fixed.

src/main/java/com/alibaba/druid/sql/ast/expr/SQLVariantRefExpr.java

@@ -105,6 +105,8 @@ public class SQLVariantRefExpr extends SQLExprImpl {
     }
 
     public SQLVariantRefExpr clone() {
-        return new SQLVariantRefExpr(name, global);
+        SQLVariantRefExpr var =  new SQLVariantRefExpr(name, global);
+        var.index = index;
+        return var;
     }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleStatementParser.java

@@ -1436,7 +1436,13 @@ public class OracleStatementParser extends SQLStatementParser {
 
         accept(Token.END);
 
-        if (lexer.token() != Token.SEMI) {
+        Token token = lexer.token();
+
+        if (token == Token.EOF) {
+            return block;
+        }
+
+        if (token != Token.SEMI) {
             String endLabel = lexer.stringVal();
             accept(Token.IDENTIFIER);
             block.setEndLabel(endLabel);