Minor fixes

Author: carlosdelest

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/RequestXContent.java

@@ -419,7 +419,7 @@ private static void checkMultiValuedParamValidity(
             );
             return;
         }
-        // Multivalued field
+
         DataType arrayType = null;
         for (Object currentValue : valueList) {
             checkParamValueValidity(entry, classification, currentValue, loc, errors);

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/evaluator/EvalMapper.java

@@ -273,18 +273,7 @@ private static Block block(Literal lit, BlockFactory blockFactory, int positions
                 if (multiValue.isEmpty()) {
                     return blockFactory.newConstantNullBlock(positions);
                 }
-                ElementType type = ElementType.NULL;
-                for (Object elem : multiValue) {
-                    if (elem != null) {
-                        type = ElementType.fromJava(elem.getClass());
-                        break;
-                    }
-                }
-                if (type == ElementType.NULL) {
-                    // all values are null
-                    return blockFactory.newConstantNullBlock(positions);
-                }
-                var wrapper = BlockUtils.wrapperFor(blockFactory, type, positions);
+                var wrapper = BlockUtils.wrapperFor(blockFactory, ElementType.fromJava(multiValue.get(0).getClass()), positions);
                 for (int i = 0; i < positions; i++) {
                     wrapper.accept(multiValue);
                 }