Add fix

Author: jfreden

server/src/main/java/org/elasticsearch/common/file/AbstractFileWatchingService.java

@@ -28,11 +28,11 @@
 import java.nio.file.attribute.BasicFileAttributes;
 import java.nio.file.attribute.FileTime;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 /**
@@ -238,16 +238,16 @@ protected final void watcherThread() {
                 key.reset();
 
                 if (key == settingsDirWatchKey) {
-                    // there may be multiple events for the same file - we only want to re-read once
-                    Set<Path> processedFiles = new HashSet<>();
-                    for (WatchEvent<?> e : events) {
-                        Path fullFile = settingsDir.resolve(e.context().toString());
-                        if (Files.isSymbolicLink(fullFile)) {
+                    Set<Path> changedPaths = events.stream()
+                        .map(event -> settingsDir.resolve(event.context().toString()))
+                        .collect(Collectors.toSet());
+                    for (var changedPath : changedPaths) {
+                        // If a symlink changed in the settings directory, it could be linked to other symlinks so reprocess all files
+                        if (Files.isSymbolicLink(changedPath)) {
                             reprocessAllChangedFilesInSettingsDir();
-                        } else if (processedFiles.add(fullFile)) {
-                            if (fileChanged(fullFile)) {
-                                process(fullFile);
-                            }
+                            break;
+                        } else if (fileChanged(changedPath)) {
+                            process(changedPath);
                         }
                     }
                 } else if (key == configDirWatchKey) {