Merge branch '6.x' into ccr-6.x

* 6.x:
  Revert "Silence IndexUpgradeIT test failures. (#30430)"
  [DOCS] Remove references to changelog and to highlights
  Revert "Mute ML upgrade test (#30458)"
  [ML] Fix BWC version for backport of #30125
  [Docs] Improve section detailing translog usage (#30573)
  [Tests] Relax allowed delta in extended_stats aggregation (#30569)
  Fail if reading from closed KeyStoreWrapper (#30394)
  [ML] Reverse engineer Grok patterns from categorization results (#30125)
  Derive max composite buffers from max content len
  Update build file due to doc file rename
  SQL: Extract SQL request and response classes (#30457)
  Remove the changelog (#30593)
  Revert "Add deprecation warning for default shards (#30587)"
  Silence IndexUpgradeIT test failures. (#30430)
  Add deprecation warning for default shards (#30587)
  [DOCS] Adds 6.4.0 release highlight pages
  [DOCS] Adds release highlight pages (#30590)
  Docs: Document how to rebuild analyzers (#30498)
  [DOCS] Fixes title capitalization in security content
  LLRest: Add equals and hashcode tests for Request (#30584)
  [DOCS] Fix realm setting names (#30499)
  [DOCS] Fix path info for various security files (#30502)
  Docs: document precision limitations of geo_bounding_box (#30540)
  Fix non existing javadocs link in RestClientTests
  Auto-expand replicas only after failing nodes (#30553)

Author: dnhatn

client/rest/src/test/java/org/elasticsearch/client/RequestTests.java

@@ -26,13 +26,16 @@
 
 import org.apache.http.Header;
 import org.apache.http.HttpEntity;
+import org.apache.http.entity.ByteArrayEntity;
 import org.apache.http.entity.ContentType;
 import org.apache.http.entity.StringEntity;
 import org.apache.http.message.BasicHeader;
 import org.apache.http.nio.entity.NStringEntity;
+import org.elasticsearch.client.HttpAsyncResponseConsumerFactory.HeapBufferedResponseConsumerFactory;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.fail;
 
@@ -151,6 +154,103 @@ public void testSetHeaders() {
         assertArrayEquals(headers, request.getHeaders());
     }
 
-    // TODO equals and hashcode
+    public void testEqualsAndHashCode() {
+        Request request = randomRequest();
+        assertEquals(request, request);
 
+        Request copy = copy(request);
+        assertEquals(request, copy);
+        assertEquals(copy, request);
+        assertEquals(request.hashCode(), copy.hashCode());
+
+        Request mutant = mutate(request);
+        assertNotEquals(request, mutant);
+        assertNotEquals(mutant, request);
+    }
+
+    private Request randomRequest() {
+        Request request = new Request(
+            randomFrom(new String[] {"GET", "PUT", "DELETE", "POST", "HEAD", "OPTIONS"}),
+            randomAsciiAlphanumOfLength(5));
+
+        int parameterCount = between(0, 5);
+        for (int i = 0; i < parameterCount; i++) {
+            request.addParameter(randomAsciiAlphanumOfLength(i), randomAsciiLettersOfLength(3));
+        }
+
+        if (randomBoolean()) {
+            if (randomBoolean()) {
+                request.setJsonEntity(randomAsciiAlphanumOfLength(10));
+            } else {
+                request.setEntity(randomFrom(new HttpEntity[] {
+                    new StringEntity(randomAsciiAlphanumOfLength(10), ContentType.APPLICATION_JSON),
+                    new NStringEntity(randomAsciiAlphanumOfLength(10), ContentType.APPLICATION_JSON),
+                    new ByteArrayEntity(randomBytesOfLength(40), ContentType.APPLICATION_JSON)
+                }));
+            }
+        }
+
+        if (randomBoolean()) {
+            int headerCount = between(1, 5);
+            Header[] headers = new Header[headerCount];
+            for (int i = 0; i < headerCount; i++) {
+                headers[i] = new BasicHeader(randomAsciiAlphanumOfLength(3), randomAsciiAlphanumOfLength(3));
+            }
+            request.setHeaders(headers);
+        }
+
+        if (randomBoolean()) {
+            request.setHttpAsyncResponseConsumerFactory(new HeapBufferedResponseConsumerFactory(1));
+        }
+
+        return request;
+    }
+
+    private Request copy(Request request) {
+        Request copy = new Request(request.getMethod(), request.getEndpoint());
+        copyMutables(request, copy);
+        return copy;
+    }
+
+    private Request mutate(Request request) {
+        if (randomBoolean()) {
+            // Mutate request or method but keep everything else constant
+            Request mutant = randomBoolean()
+                ? new Request(request.getMethod() + "m", request.getEndpoint())
+                : new Request(request.getMethod(), request.getEndpoint() + "m");
+            copyMutables(request, mutant);
+            return mutant;
+        }
+        Request mutant = copy(request);
+        int mutationType = between(0, 3);
+        switch (mutationType) {
+        case 0:
+            mutant.addParameter(randomAsciiAlphanumOfLength(mutant.getParameters().size() + 4), "extra");
+            return mutant;
+        case 1:
+            mutant.setJsonEntity("mutant"); // randomRequest can't produce this value
+            return mutant;
+        case 2:
+            if (mutant.getHeaders().length > 0) {
+                mutant.setHeaders(new Header[0]);
+            } else {
+                mutant.setHeaders(new BasicHeader("extra", "m"));
+            }
+            return mutant;
+        case 3:
+            mutant.setHttpAsyncResponseConsumerFactory(new HeapBufferedResponseConsumerFactory(5));
+            return mutant;
+        default:
+            throw new UnsupportedOperationException("Unknown mutation type [" + mutationType + "]");
+        }
+    }
+
+    private void copyMutables(Request from, Request to) {
+        for (Map.Entry<String, String> param : from.getParameters().entrySet()) {
+            to.addParameter(param.getKey(), param.getValue());
+        }
+        to.setEntity(from.getEntity());
+        to.setHeaders(from.getHeaders());
+        to.setHttpAsyncResponseConsumerFactory(from.getHttpAsyncResponseConsumerFactory());
+    }
 }

client/rest/src/test/java/org/elasticsearch/client/RestClientTests.java

@@ -96,7 +96,7 @@ public void onFailure(Exception exception) {
     }
 
     /**
-     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link RequestTests#testSetParameters()}.
+     * @deprecated will remove method in 7.0 but needs tests until then. Replaced by {@link RequestTests#testAddParameters()}.
      */
     @Deprecated
     public void testPerformOldStyleAsyncWithNullParams() throws Exception {