diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 728a3b98e638e..82e2a3deadf1e 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -3301,13 +3301,21 @@ class ActivityStack<T extends StackWindowController> extends ConfigurationContai
 
         final ActivityRecord next = topRunningActivityLocked();
         final String myReason = reason + " adjustFocus";
+
         if (next != r) {
             if (next != null && StackId.keepFocusInStackIfPossible(mStackId) && isFocusable()) {
                 // For freeform, docked, and pinned stacks we always keep the focus within the
                 // stack as long as there is a running activity.
                 return;
             } else {
+                // Task is not guaranteed to be non-null. For example, destroying the
+                // {@link ActivityRecord} will disassociate the task from the activity.
                 final TaskRecord task = r.getTask();
+
+                if (task == null) {
+                    throw new IllegalStateException("activity no longer associated with task:" + r);
+                }
+
                 final boolean isAssistantOrOverAssistant = task.getStack().isAssistantStack() ||
                         task.isOverAssistantStack();
                 if (r.frontOfTask && isATopFinishingTask(task)
@@ -3373,8 +3381,8 @@ class ActivityStack<T extends StackWindowController> extends ConfigurationContai
                     if (DEBUG_STATES) Slog.d(TAG_STATES, "no-history finish of " + r);
                     if (requestFinishActivityLocked(r.appToken, Activity.RESULT_CANCELED, null,
                             "stop-no-history", false)) {
-                        // Activity was finished, no need to continue trying to schedule stop.
-                        adjustFocusedActivityStackLocked(r, "stopActivityFinished");
+                        // If {@link requestFinishActivityLocked} returns {@code true},
+                        // {@link adjustFocusedActivityStackLocked} would have been already called.
                         r.resumeKeyDispatchingLocked();
                         return;
                     }
diff --git a/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java b/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java
index 58166b6c1ac5b..c87eaed5c9542 100644
--- a/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java
+++ b/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java
@@ -22,6 +22,7 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import android.content.ComponentName;
+import android.content.pm.ActivityInfo;
 import android.platform.test.annotations.Presubmit;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
@@ -84,4 +85,16 @@ public class ActivityStackTests extends ActivityTestsBase {
         // Make sure the resumed activity is untouched.
         assertEquals(testStack.mResumedActivity, activityRecord);
     }
+
+    @Test
+    public void testStopActivityWhenActivityDestroyed() throws Exception {
+        final ActivityManagerService service = createActivityManagerService();
+        final TaskRecord task = createTask(service, testActivityComponent, TEST_STACK_ID);
+        final ActivityRecord activityRecord = createActivity(service, testActivityComponent, task);
+        activityRecord.info.flags |= ActivityInfo.FLAG_NO_HISTORY;
+        final ActivityStack testStack = service.mStackSupervisor.getStack(TEST_STACK_ID);
+        service.mStackSupervisor.setFocusStackUnchecked("testStopActivityWithDestroy", testStack);
+
+        testStack.stopActivityLocked(activityRecord);
+    }
 }
diff --git a/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java b/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java
index 0827084420329..3fc2c1246c596 100644
--- a/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java
+++ b/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java
@@ -161,6 +161,11 @@ public class ActivityTestsBase {
         void moveHomeStackToFront(String reason) {
         }
 
+        @Override
+        boolean moveHomeStackTaskToTop(String reason) {
+            return true;
+        }
+
         // Invoked during {@link ActivityStack} creation.
         @Override
         void updateUIDsPresentOnDisplay() {