Merge branch '9.1' into backport/9.1/pr-130943

Author: nik9000

README.asciidoc

@@ -275,7 +275,7 @@ For the complete Elasticsearch documentation visit
 https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html[elastic.co].
 
 For information about our documentation processes, see the
-xref:docs/README.asciidoc[docs README].
+xref:https://github.com/elastic/elasticsearch/blob/main/docs/README.md[docs README].
 
 [[examples]]
 == Examples and guides

docs/changelog/130776.yaml

@@ -0,0 +1,6 @@
+pr: 130776
+summary: Fix msearch request parsing when index expression is null
+area: Search
+type: bug
+issues:
+ - 129631

docs/reference/elasticsearch/index.md

@@ -1,4 +1,4 @@
-# Elasticsearch and index management
+# Elasticsearch
 
 This section contains reference information for {{es}} and index management features.
 
@@ -7,7 +7,7 @@ To learn more about {{es}} features and how to get started, refer to the [{{es}}
 For more details about query and scripting languages, check these sections:
 * [Query languages](../query-languages/index.md)
 * [Scripting languages](../scripting-languages/index.md)
- 
+
 {{es}} also provides the following REST APIs:
 
 * [{{es}} API](https://www.elastic.co/docs/api/doc/elasticsearch)

docs/reference/elasticsearch/rest-apis/index.md

@@ -89,6 +89,7 @@ buildParams.bwcVersions.withWireCompatible { bwcVersion, baseName ->
         setting 'health.master_history.no_master_transitions_threshold', '10'
       }
       requiresFeature 'es.index_mode_feature_flag_registered', Version.fromString("8.0.0")
+      requiresFeature 'sub_objects_auto', Version.fromString("8.16.0")
       if (bwcVersion.before(Version.fromString("8.18.0"))) {
         jvmArgs '-da:org.elasticsearch.index.mapper.DocumentMapper'
         jvmArgs '-da:org.elasticsearch.index.mapper.MapperService'

qa/mixed-cluster/build.gradle

@@ -560,6 +560,9 @@ public static Map<String, Object> nodeMapValue(Object node, String desc) {
      * Otherwise the node is treated as a comma-separated string.
      */
     public static String[] nodeStringArrayValue(Object node) {
+        if (node == null) {
+            throw new ElasticsearchParseException("Expected a list of strings but got null");
+        }
         if (isArray(node)) {
             List<?> list = (List<?>) node;
             String[] arr = new String[list.size()];

server/src/main/java/org/elasticsearch/common/xcontent/support/XContentMapValues.java

@@ -1366,11 +1366,12 @@ public RefreshStats refreshStats() {
     }
 
     public FlushStats flushStats() {
+        final Engine engine = getEngineOrNull();
         return new FlushStats(
             flushMetric.count(),
             periodicFlushMetric.count(),
             TimeUnit.NANOSECONDS.toMillis(flushMetric.sum()),
-            getEngineOrNull() != null ? getEngineOrNull().getTotalFlushTimeExcludingWaitingOnLockInMillis() : 0L
+            engine != null ? engine.getTotalFlushTimeExcludingWaitingOnLockInMillis() : 0L
         );
     }
 

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -9,6 +9,7 @@
 
 package org.elasticsearch.action.search;
 
+import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.common.CheckedBiConsumer;
 import org.elasticsearch.common.Strings;
@@ -537,6 +538,14 @@ public void testFailOnExtraCharacters() throws IOException {
         }
     }
 
+    public void testNullIndex() throws IOException {
+        ElasticsearchParseException e = expectThrows(ElasticsearchParseException.class, () -> parseMultiSearchRequestFromString("""
+            {"index": null}
+            { "query": {"match_all": {}}}
+            """));
+        assertThat(e.getMessage(), containsString("Expected a list of strings but got null"));
+    }
+
     private static MultiSearchRequest mutate(MultiSearchRequest searchRequest) throws IOException {
         MultiSearchRequest mutation = copyRequest(searchRequest);
         List<CheckedRunnable<IOException>> mutators = new ArrayList<>();

server/src/test/java/org/elasticsearch/action/search/MultiSearchRequestTests.java

@@ -78,7 +78,7 @@ public void testOldIndicesCheck() {
 
     public void testOldIndicesCheckWithOnlyNewIndices() {
         // This tests what happens when any old indices that we have are closed. We expect no deprecation warning.
-        int newOpenIndexCount = randomIntBetween(0, 100);
+        int newOpenIndexCount = randomIntBetween(1, 100);
         int newClosedIndexCount = randomIntBetween(0, 100);
 
         Map<String, IndexMetadata> nameToIndexMetadata = new HashMap<>();

x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/DataStreamDeprecationCheckerTests.java

@@ -321,6 +321,7 @@ public TransportVersion getMinimalSupportedVersion() {
     private static class AppendBlocksIterator implements ReleasableIterator<Page> {
         private final Page page;
         private final ReleasableIterator<Block[]> next;
+        private boolean closed = false;
 
         private int positionOffset;
 
@@ -348,7 +349,15 @@ public final Page next() {
                 for (int b = 0; b < page.getBlockCount(); b++) {
                     page.getBlock(b).incRef();
                 }
-                return page.appendBlocks(read);
+                final Page result = page.appendBlocks(read);
+                // We need to release the blocks of the page in this iteration instead of delaying to the next,
+                // because the blocks of this page are now shared with the output page. The output page can be
+                // passed to a separate driver, which may run concurrently with this driver, leading to data races
+                // of references in AbstractNonThreadSafeRefCounted, which is not thread-safe.
+                // An alternative would be to make RefCounted for Vectors/Blocks thread-safe when they are about
+                // to be shared with other drivers via #allowPassingToDifferentDriver.
+                close();
+                return result;
             }
             Block[] newBlocks = new Block[page.getBlockCount() + read.length];
             System.arraycopy(read, 0, newBlocks, page.getBlockCount(), read.length);
@@ -368,7 +377,10 @@ public final Page next() {
 
         @Override
         public void close() {
-            Releasables.closeExpectNoException(page::releaseBlocks, next);
+            if (closed == false) {
+                closed = true;
+                Releasables.closeExpectNoException(page::releaseBlocks, next);
+            }
         }
     }
 }