Replace NOT operator with explicit false check - part 7 (#68454)

Part 7.

We have an in-house rule to compare explicitly against `false` instead
of using the logical not operator (`!`). However, this hasn't
historically been enforced, meaning that there are many violations in
the source at present.

We now have a Checkstyle rule that can detect these cases, but before we
can turn it on, we need to fix the existing violations. This is being
done over a series of PRs, since there are a lot to fix.

Author: pugnascotia

libs/dissect/src/main/java/org/elasticsearch/dissect/DissectKey.java

@@ -90,7 +90,7 @@ public final class DissectKey {
                 break;
         }
 
-        if (name == null || (name.isEmpty() && !skip)) {
+        if (name == null || (name.isEmpty() && skip == false)) {
             throw new DissectException.KeyParse(key, "The key name could not be determined");
         }
     }

server/src/internalClusterTest/java/org/elasticsearch/snapshots/SharedClusterSnapshotRestoreIT.java

@@ -1658,7 +1658,7 @@ public void testGetSnapshotsFromIndexBlobOnly() throws Exception {
             boolean atLeastOne = false;
             List<String> indices = new ArrayList<>();
             for (int j = 0; j < numIndices; j++) {
-                if (all || randomBoolean() || !atLeastOne) {
+                if (all || randomBoolean() || atLeastOne == false) {
                     indices.add("test-idx-" + j);
                     atLeastOne = true;
                 }

server/src/main/java/org/elasticsearch/bootstrap/BootstrapChecks.java

@@ -306,7 +306,7 @@ static class MlockallCheck implements BootstrapCheck {
 
         @Override
         public BootstrapCheckResult check(BootstrapContext context) {
-            if (BootstrapSettings.MEMORY_LOCK_SETTING.get(context.settings()) && !isMemoryLocked()) {
+            if (BootstrapSettings.MEMORY_LOCK_SETTING.get(context.settings()) && isMemoryLocked() == false) {
                 return BootstrapCheckResult.failure("memory locking requested for elasticsearch process but memory is not locked");
             } else {
                 return BootstrapCheckResult.success();
@@ -529,7 +529,7 @@ static class SystemCallFilterCheck implements BootstrapCheck {
 
         @Override
         public BootstrapCheckResult check(BootstrapContext context) {
-            if (BootstrapSettings.SYSTEM_CALL_FILTER_SETTING.get(context.settings()) && !isSystemCallFilterInstalled()) {
+            if (BootstrapSettings.SYSTEM_CALL_FILTER_SETTING.get(context.settings()) && isSystemCallFilterInstalled() == false) {
                 final String message =  "system call filters failed to install; " +
                         "check the logs and fix your configuration or disable system call filters at your own risk";
                 return BootstrapCheckResult.failure(message);

server/src/main/java/org/elasticsearch/cluster/ClusterName.java

@@ -57,9 +57,7 @@ public boolean equals(Object o) {
 
         ClusterName that = (ClusterName) o;
 
-        if (value != null ? !value.equals(that.value) : that.value != null) return false;
-
-        return true;
+        return Objects.equals(value, that.value);
     }
 
     @Override

server/src/main/java/org/elasticsearch/cluster/metadata/IndexNameExpressionResolver.java

@@ -270,7 +270,7 @@ Index[] concreteIndices(Context context, String... indexExpressions) {
                     concreteIndices.add(writeIndex.getIndex());
                 }
             } else {
-                if (indexAbstraction.getIndices().size() > 1 && !options.allowAliasesToMultipleIndices()) {
+                if (indexAbstraction.getIndices().size() > 1 && options.allowAliasesToMultipleIndices() == false) {
                     String[] indexNames = new String[indexAbstraction.getIndices().size()];
                     int i = 0;
                     for (IndexMetadata indexMetadata : indexAbstraction.getIndices()) {
@@ -828,7 +828,7 @@ public List<String> resolve(Context context, List<String> expressions) {
             if (result == null) {
                 return expressions;
             }
-            if (result.isEmpty() && !options.allowNoIndices()) {
+            if (result.isEmpty() && options.allowNoIndices() == false) {
                 IndexNotFoundException infe = new IndexNotFoundException((String)null);
                 infe.setResources("index_or_alias", expressions.toArray(new String[0]));
                 throw infe;

server/src/main/java/org/elasticsearch/cluster/metadata/Metadata.java

@@ -1480,7 +1480,7 @@ public static void toXContent(Metadata metadata, XContentBuilder builder, ToXCon
             metadata.coordinationMetadata().toXContent(builder, params);
             builder.endObject();
 
-            if (context != XContentContext.API && !metadata.persistentSettings().isEmpty()) {
+            if (context != XContentContext.API && metadata.persistentSettings().isEmpty() == false) {
                 builder.startObject("settings");
                 metadata.persistentSettings().toXContent(builder, new MapParams(Collections.singletonMap("flat_settings", "true")));
                 builder.endObject();

server/src/main/java/org/elasticsearch/cluster/routing/ShardRouting.java

@@ -23,6 +23,7 @@
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * {@link ShardRouting} immutably encapsulates information about shard
@@ -519,43 +520,25 @@ public boolean isRelocationSourceOf(ShardRouting other) {
 
     /** returns true if the current routing is identical to the other routing in all but meta fields, i.e., unassigned info */
     public boolean equalsIgnoringMetadata(ShardRouting other) {
-        if (primary != other.primary) {
-            return false;
-        }
-        if (shardId != null ? !shardId.equals(other.shardId) : other.shardId != null) {
-            return false;
-        }
-        if (currentNodeId != null ? !currentNodeId.equals(other.currentNodeId) : other.currentNodeId != null) {
-            return false;
-        }
-        if (relocatingNodeId != null ? !relocatingNodeId.equals(other.relocatingNodeId) : other.relocatingNodeId != null) {
-            return false;
-        }
-        if (allocationId != null ? !allocationId.equals(other.allocationId) : other.allocationId != null) {
-            return false;
-        }
-        if (state != other.state) {
-            return false;
-        }
-        if (recoverySource != null ? !recoverySource.equals(other.recoverySource) : other.recoverySource != null) {
-            return false;
-        }
-        return true;
+        return primary == other.primary
+            && Objects.equals(shardId, other.shardId)
+            && Objects.equals(currentNodeId, other.currentNodeId)
+            && Objects.equals(relocatingNodeId, other.relocatingNodeId)
+            && Objects.equals(allocationId, other.allocationId)
+            && state == other.state
+            && Objects.equals(recoverySource, other.recoverySource);
     }
 
     @Override
     public boolean equals(Object o) {
         if (this == o) {
             return true;
         }
-        if (o == null || !(o instanceof ShardRouting)) {
+        if (o == null || getClass() != o.getClass()) {
             return false;
         }
         ShardRouting that = (ShardRouting) o;
-        if (unassignedInfo != null ? !unassignedInfo.equals(that.unassignedInfo) : that.unassignedInfo != null) {
-            return false;
-        }
-        return equalsIgnoringMetadata(that);
+        return Objects.equals(unassignedInfo, that.unassignedInfo) && equalsIgnoringMetadata(that);
     }
 
     /**

server/src/main/java/org/elasticsearch/gateway/PrimaryShardAllocator.java

@@ -136,7 +136,7 @@ public AllocateUnassignedDecision makeAllocationDecision(final ShardRouting unas
                          unassignedShard.index(), unassignedShard.id(), unassignedShard, decidedNode.nodeShardState.getNode());
             node = decidedNode.nodeShardState.getNode();
             allocationId = decidedNode.nodeShardState.allocationId();
-        } else if (nodesToAllocate.throttleNodeShards.isEmpty() && !nodesToAllocate.noNodeShards.isEmpty()) {
+        } else if (nodesToAllocate.throttleNodeShards.isEmpty() && nodesToAllocate.noNodeShards.isEmpty() == false) {
             // The deciders returned a NO decision for all nodes with shard copies, so we check if primary shard
             // can be force-allocated to one of the nodes.
             nodesToAllocate = buildNodesToAllocate(allocation, nodeShardsResult.orderedAllocationCandidates, unassignedShard, true);

server/src/main/java/org/elasticsearch/http/DefaultRestChannel.java

@@ -145,7 +145,7 @@ private void setHeaderField(HttpResponse response, String headerField, String va
     }
 
     private void setHeaderField(HttpResponse response, String headerField, String value, boolean override) {
-        if (override || !response.containsHeader(headerField)) {
+        if (override || response.containsHeader(headerField) == false) {
             response.addHeader(headerField, value);
         }
     }

server/src/main/java/org/elasticsearch/ingest/IngestService.java

@@ -604,7 +604,7 @@ static String getProcessorName(Processor processor) {
             sb.append(pipelineName);
         }
         String tag = processor.getTag();
-        if(tag != null && !tag.isEmpty()){
+        if (tag != null && tag.isEmpty() == false) {
             sb.append(":");
             sb.append(tag);
         }