update test

Author: jdconrad

server/src/main/java/org/elasticsearch/features/InfrastructureFeatures.java

@@ -43,9 +43,14 @@ public class InfrastructureFeatures implements FeatureSpecification {
     public static final NodeFeature CURRENT_VERSION = new NodeFeature("ES_" + RestApiVersion.current());
     private static final NodeFeature PREVIOUS_VERSION = new NodeFeature("ES_" + RestApiVersion.previous(), true);
 
+    public static final NodeFeature JACKSON_COMBINE_UNICODE_SURROGATES_IN_UTF8 = new NodeFeature(
+        "jackson_combine_unicode_surrogates_in_utf8",
+        true
+    );
+
     @Override
     public Set<NodeFeature> getFeatures() {
-        return Set.of(CURRENT_VERSION, PREVIOUS_VERSION);
+        return Set.of(CURRENT_VERSION, PREVIOUS_VERSION, JACKSON_COMBINE_UNICODE_SURROGATES_IN_UTF8);
     }
 
     @Override

x-pack/plugin/logsdb/qa/rolling-upgrade/src/javaRestTest/java/org/elasticsearch/xpack/logsdb/FlattenedRollingUpgradeIT.java

@@ -24,6 +24,7 @@
 import org.elasticsearch.datageneration.datasource.DefaultObjectGenerationHandler;
 import org.elasticsearch.datageneration.matchers.MatchResult;
 import org.elasticsearch.datageneration.matchers.Matcher;
+import org.elasticsearch.features.InfrastructureFeatures;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.test.rest.ObjectPath;
@@ -86,6 +87,12 @@ public String generateFieldName() {
                         if (candidate.contains("\0")) {
                             continue;
                         }
+                        if (oldClusterHasFeature(InfrastructureFeatures.JACKSON_COMBINE_UNICODE_SURROGATES_IN_UTF8) == false) {
+                            candidate = stripUnpairedSurrogates(candidate);
+                            if (candidate.isBlank()) {
+                                continue;
+                            }
+                        }
                         return candidate;
                     }
                 }
@@ -270,4 +277,20 @@ public void testIndexing() throws IOException {
         }
     }
 
+    private static String stripUnpairedSurrogates(String s) {
+        StringBuilder sb = new StringBuilder(s.length());
+        for (int i = 0; i < s.length(); i++) {
+            char c = s.charAt(i);
+            if (Character.isHighSurrogate(c)) {
+                if (i + 1 < s.length() && Character.isLowSurrogate(s.charAt(i + 1))) {
+                    sb.append(c);
+                    sb.append(s.charAt(++i));
+                }
+            } else if (Character.isLowSurrogate(c) == false) {
+                sb.append(c);
+            }
+        }
+        return sb.toString();
+    }
+
 }