From 76cf56933fac0ba221ca61d1e8263f56feac0011 Mon Sep 17 00:00:00 2001
From: Michael Froh <froh@amazon.com>
Date: Thu, 9 Jan 2025 17:31:34 -0800
Subject: [PATCH] Always write doc_values param to mapping for wildcard field

I made a mistake making this parameter default to false. In 3.0,
I would like to switch the default to true. An index upgraded from
2.x with the default (false) value should specifically emit the
value to avoid implicitly picking up the new default (true).

Signed-off-by: Michael Froh <froh@amazon.com>
---
 .../java/org/opensearch/index/mapper/WildcardFieldMapper.java   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java
index e43e3bda692e7..cd30c8a4ff7d0 100644
--- a/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/WildcardFieldMapper.java
@@ -101,7 +101,7 @@ public static final class Builder extends ParametrizedFieldMapper.Builder {
         );
         private final Parameter<String> normalizer = Parameter.stringParam("normalizer", false, m -> toType(m).normalizerName, "default");
         private final Parameter<Map<String, String>> meta = Parameter.metaParam();
-        private final Parameter<Boolean> hasDocValues = Parameter.docValuesParam(m -> toType(m).hasDocValues, false);
+        private final Parameter<Boolean> hasDocValues = Parameter.docValuesParam(m -> toType(m).hasDocValues, false).alwaysSerialize();
         private final IndexAnalyzers indexAnalyzers;
 
         public Builder(String name, IndexAnalyzers indexAnalyzers) {