Correct the Elvis (?:) operator and add null coalescing (??) operator

Author: markt-asf

java/org/apache/el/parser/AstElvis.java

@@ -20,6 +20,7 @@
 
 import jakarta.el.ELException;
 
+import org.apache.el.lang.ELSupport;
 import org.apache.el.lang.EvaluationContext;
 
 public class AstElvis extends SimpleNode {
@@ -36,10 +37,11 @@ public Class<?> getType(EvaluationContext ctx) throws ELException {
     @Override
     public Object getValue(EvaluationContext ctx) throws ELException {
         Object obj0 = this.children[0].getValue(ctx);
-        if (obj0 == null) {
-            return this.children[1].getValue(ctx);
-        } else {
+        Boolean b = ELSupport.coerceToBoolean(ctx, obj0, true);
+        if (b.booleanValue()) {
             return obj0;
+        } else {
+            return this.children[1].getValue(ctx);
         }
     }
 }

java/org/apache/el/parser/AstNullCoalescing.java

@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/* Generated By:JJTree: Do not edit this line. AstNullCoalescing.java Version 7.0 */
+/* JavaCCOptions:MULTI=true,NODE_USES_PARSER=false,VISITOR=false,TRACK_TOKENS=false,NODE_PREFIX=Ast,NODE_EXTENDS=,NODE_FACTORY=,SUPPORT_CLASS_VISIBILITY_PUBLIC=true */
+package org.apache.el.parser;
+
+import jakarta.el.ELException;
+
+import org.apache.el.lang.EvaluationContext;
+
+public class AstNullCoalescing extends SimpleNode {
+    public AstNullCoalescing(int id) {
+        super(id);
+    }
+
+    @Override
+    public Class<?> getType(EvaluationContext ctx) throws ELException {
+        Object val = this.getValue(ctx);
+        return (val != null) ? val.getClass() : null;
+    }
+
+    @Override
+    public Object getValue(EvaluationContext ctx) throws ELException {
+        Object obj0 = this.children[0].getValue(ctx);
+        if (obj0 == null) {
+            return this.children[1].getValue(ctx);
+        } else {
+            return obj0;
+        }
+    }
+}
+/* JavaCC - OriginalChecksum=7f7cabdfdef87abc6e6a22ac32db0871 (do not edit this line) */