test: Add inversePrecedence regression tests for #861 and #864

Add two new tests to LockStepTest:

- lockInverseOrderWithLabel: verifies inversePrecedence=true grants the
  lock to the newest build when locking by label (JENKINS-40787, #861)

- lockInverseOrderMixedDifferentJobs: verifies each waiting job's own
  inversePrecedence flag controls queue ordering when using separate
  pipeline jobs with mixed settings (JENKINS-41070, #864)

Author: mPokornyETM

src/test/java/org/jenkins/plugins/lockableresources/LockStepTest.java

@@ -557,6 +557,155 @@ void lockInverseOrder2(JenkinsRule j) throws Exception {
         j.assertBuildStatusSuccess(j.waitForCompletion(b6));
     }
 
+    /**
+     * Verify that inversePrecedence=true grants the lock to the newest build
+     * when locking by <b>label</b> (not named resource).
+     *
+     * <pre>
+     * start time | build | label  | inversePrecedence
+     * -----------|-------|--------|-------------------
+     * 00:01      | b1    | label1 | true   (acquires)
+     * 00:02      | b2    | label1 | true   (waits)
+     * 00:03      | b3    | label1 | true   (waits)
+     *
+     * expected lock order: b1 -> b3 -> b2
+     * </pre>
+     */
+    @Test
+    @Issue({"JENKINS-40787", "GITHUB-861"})
+    void lockInverseOrderWithLabel(JenkinsRule j) throws Exception {
+        LockableResourcesManager.get().createResourceWithLabel("resource1", "label1");
+        WorkflowJob p = j.jenkins.createProject(WorkflowJob.class, "p");
+        p.setDefinition(new CpsFlowDefinition("""
+                lock(label: 'label1', inversePrecedence: true) {
+                    semaphore 'wait-inside'
+                }
+                echo 'Finish'""", true));
+
+        WorkflowRun b1 = p.scheduleBuild2(0).waitForStart();
+        SemaphoreStep.waitForStart("wait-inside/1", b1);
+
+        WorkflowRun b2 = p.scheduleBuild2(0).waitForStart();
+        j.waitForMessage("[Label: label1] is locked by build " + b1.getFullDisplayName(), b2);
+        isPaused(b2, 1, 1);
+
+        WorkflowRun b3 = p.scheduleBuild2(0).waitForStart();
+        j.waitForMessage("[Label: label1] is locked by build " + b1.getFullDisplayName(), b3);
+        isPaused(b3, 1, 1);
+
+        // Release b1 — b3 (newest) must acquire before b2
+        SemaphoreStep.success("wait-inside/1", null);
+        j.waitForMessage("Lock released on resource", b1);
+        j.assertBuildStatusSuccess(j.waitForCompletion(b1));
+
+        SemaphoreStep.waitForStart("wait-inside/2", b3);
+        j.waitForMessage("Trying to acquire lock on [Label: label1]", b3);
+
+        SemaphoreStep.success("wait-inside/2", null);
+        j.waitForMessage("Lock released on resource", b3);
+        j.assertBuildStatusSuccess(j.waitForCompletion(b3));
+
+        SemaphoreStep.waitForStart("wait-inside/3", b2);
+        j.waitForMessage("Trying to acquire lock on [Label: label1]", b2);
+
+        SemaphoreStep.success("wait-inside/3", null);
+        j.assertBuildStatusSuccess(j.waitForCompletion(b2));
+    }
+
+    /**
+     * Verify that each waiting job's own {@code inversePrecedence} flag controls
+     * queue ordering, not the releasing job's flag. Uses <b>separate</b> pipeline
+     * jobs to match the original report.
+     *
+     * <pre>
+     * start time | job  | resource  | inversePrecedence
+     * -----------|------|-----------|-------------------
+     * 00:01      | pA#1 | resource1 | true   (acquires)
+     * 00:02      | pB#1 | resource1 | false  (waits — FIFO)
+     * 00:03      | pA#2 | resource1 | true   (waits — inversePrecedence, front)
+     * 00:04      | pB#2 | resource1 | false  (waits — FIFO, behind pB#1)
+     *
+     * expected lock order: pA#1 -> pA#2 -> pB#1 -> pB#2
+     * </pre>
+     */
+    @Test
+    @Issue({"JENKINS-41070", "GITHUB-864"})
+    void lockInverseOrderMixedDifferentJobs(JenkinsRule j) throws Exception {
+        LockableResourcesManager.get().createResourceWithLabel("resource1", "label1");
+
+        // Job A — inversePrecedence = true
+        WorkflowJob pA = j.jenkins.createProject(WorkflowJob.class, "pA");
+        pA.setDefinition(new CpsFlowDefinition("""
+                lock(resource: 'resource1', inversePrecedence: true) {
+                    echo 'locked-pA'
+                    semaphore 'wait-inside'
+                }
+                echo 'Finish'""", true));
+
+        // Job B — inversePrecedence = false
+        WorkflowJob pB = j.jenkins.createProject(WorkflowJob.class, "pB");
+        pB.setDefinition(new CpsFlowDefinition("""
+                lock(resource: 'resource1', inversePrecedence: false) {
+                    echo 'locked-pB'
+                    semaphore 'wait-inside'
+                }
+                echo 'Finish'""", true));
+
+        // pA#1 acquires the lock
+        WorkflowRun a1 = pA.scheduleBuild2(0).waitForStart();
+        SemaphoreStep.waitForStart("wait-inside/1", a1);
+        j.assertLogContains("locked-pA", a1);
+
+        // pB#1 waits (inversePrecedence=false → back of queue)
+        WorkflowRun b1 = pB.scheduleBuild2(0).waitForStart();
+        j.waitForMessage("[resource1] is locked by build " + a1.getFullDisplayName(), b1);
+
+        // pA#2 waits (inversePrecedence=true → front of queue)
+        WorkflowRun a2 = pA.scheduleBuild2(0).waitForStart();
+        j.waitForMessage("[resource1] is locked by build " + a1.getFullDisplayName(), a2);
+
+        // pB#2 waits (inversePrecedence=false → back of queue, behind pB#1)
+        WorkflowRun b2 = pB.scheduleBuild2(0).waitForStart();
+        j.waitForMessage("[resource1] is locked by build " + a1.getFullDisplayName(), b2);
+
+        // Verify only a1 has the lock so far
+        j.assertLogNotContains("locked-pA", a2);
+        j.assertLogNotContains("locked-pB", b1);
+        j.assertLogNotContains("locked-pB", b2);
+
+        // Release pA#1 — pA#2 (inversePrecedence=true) must acquire next
+        SemaphoreStep.success("wait-inside/1", null);
+        j.waitForMessage("Lock released on resource", a1);
+
+        SemaphoreStep.waitForStart("wait-inside/2", a2);
+        j.assertLogContains("locked-pA", a2);
+        j.assertLogNotContains("locked-pB", b1);
+        j.assertLogNotContains("locked-pB", b2);
+
+        // Release pA#2 — pB#1 (FIFO among false) must acquire next
+        SemaphoreStep.success("wait-inside/2", null);
+        j.waitForMessage("Lock released on resource", a2);
+
+        SemaphoreStep.waitForStart("wait-inside/3", b1);
+        j.assertLogContains("locked-pB", b1);
+        j.assertLogNotContains("locked-pB", b2);
+
+        // Release pB#1 — pB#2 gets the lock last
+        SemaphoreStep.success("wait-inside/3", null);
+        j.waitForMessage("Lock released on resource", b1);
+
+        SemaphoreStep.waitForStart("wait-inside/4", b2);
+        j.assertLogContains("locked-pB", b2);
+
+        // Release pB#2 and verify all succeed
+        SemaphoreStep.success("wait-inside/4", null);
+
+        j.assertBuildStatusSuccess(j.waitForCompletion(a1));
+        j.assertBuildStatusSuccess(j.waitForCompletion(a2));
+        j.assertBuildStatusSuccess(j.waitForCompletion(b1));
+        j.assertBuildStatusSuccess(j.waitForCompletion(b2));
+    }
+
     /**
      * start time | job | resource  | priority
      * ------     |---  |---        |---