Stop builds in the order they are provided from the CLI (#6456)

core/src/main/java/jenkins/cli/StopBuildsCommand.java

@@ -31,8 +31,9 @@ import hudson.model.Item;
 import hudson.model.Job;
 import hudson.model.Run;
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 import jenkins.model.Jenkins;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
@@ -55,7 +56,8 @@ public class StopBuildsCommand extends CLICommand {
     @Override
     protected int run() throws Exception {
         Jenkins jenkins = Jenkins.get();
-        final HashSet<String> names = new HashSet<>(jobNames);
+        // Deduplicate job names, but preserve the order specified by the user.
+        final Set<String> names = new LinkedHashSet<>(jobNames);
 
         final List<Job> jobsToStop = new ArrayList<>();
         for (final String jobName : names) {