diff --git a/java/java-psi-api/src/com/intellij/psi/PsiClass.java b/java/java-psi-api/src/com/intellij/psi/PsiClass.java
index 64dd27190706..a60d56a725cd 100644
--- a/java/java-psi-api/src/com/intellij/psi/PsiClass.java
+++ b/java/java-psi-api/src/com/intellij/psi/PsiClass.java
@@ -195,7 +195,7 @@ public interface PsiClass
   @NotNull PsiMethod[] getAllMethods();
 
   /**
-   * Returns the list of inner classes for the class and all its superclasses..
+   * Returns the list of inner classes for the class and all its superclasses.
    *
    * @return the list of inner classes.
    */
diff --git a/platform/testFramework/src/com/intellij/testFramework/PsiTestUtil.java b/platform/testFramework/src/com/intellij/testFramework/PsiTestUtil.java
index 76567ea0195c..e0394457bd88 100644
--- a/platform/testFramework/src/com/intellij/testFramework/PsiTestUtil.java
+++ b/platform/testFramework/src/com/intellij/testFramework/PsiTestUtil.java
@@ -114,7 +114,7 @@ public class PsiTestUtil {
     return vDir;
   }
 
-  public static void removeAllRoots(Module module, Sdk jdk) {
+  public static void removeAllRoots(@NotNull Module module, Sdk jdk) {
     ModuleRootModificationUtil.updateModel(module, model -> {
       model.clear();
       model.setSdk(jdk);
diff --git a/platform/util/src/com/intellij/util/SmartFMap.java b/platform/util/src/com/intellij/util/SmartFMap.java
index a4b95a189bb5..cba92de577d0 100644
--- a/platform/util/src/com/intellij/util/SmartFMap.java
+++ b/platform/util/src/com/intellij/util/SmartFMap.java
@@ -30,7 +30,7 @@ import java.util.*;
 public class SmartFMap<K,V> implements Map<K,V> {
   private static final SmartFMap EMPTY = new SmartFMap(ArrayUtil.EMPTY_OBJECT_ARRAY);
   private static final int ARRAY_THRESHOLD = 8;
-  private final Object myMap;
+  private final Object myMap; // Object[] for map sizes up to ARRAY_THRESHOLD or Map
 
   private SmartFMap(Object map) {
     myMap = map;
@@ -41,12 +41,12 @@ public class SmartFMap<K,V> implements Map<K,V> {
   }
 
   public SmartFMap<K, V> plus(@NotNull K key, V value) {
-    return new SmartFMap<K, V>(doPlus(myMap, key, value, false));
+    return new SmartFMap<K, V>(doPlus(myMap, key, value));
   }
 
-  private static Object doPlus(Object oldMap, Object key, Object value, boolean inPlace) {
+  private static Object doPlus(Object oldMap, Object key, Object value) {
     if (oldMap instanceof Map) {
-      Map newMap = inPlace ? (Map)oldMap : new THashMap((Map)oldMap);
+      Map newMap = new THashMap((Map)oldMap);
       newMap.put(key, value);
       return newMap;
     }
@@ -54,10 +54,8 @@ public class SmartFMap<K,V> implements Map<K,V> {
     Object[] array = (Object[])oldMap;
     for (int i = 0; i < array.length; i += 2) {
       if (key.equals(array[i])) {
-        Object[] newArray = inPlace ? array : new Object[array.length];
-        if (!inPlace) {
-          System.arraycopy(array, 0, newArray, 0, array.length);
-        }
+        Object[] newArray = new Object[array.length];
+        System.arraycopy(array, 0, newArray, 0, array.length);
         newArray[i + 1] = value;
         return newArray;
       }
diff --git a/platform/util/src/com/intellij/util/messages/impl/MessageBusConnectionImpl.java b/platform/util/src/com/intellij/util/messages/impl/MessageBusConnectionImpl.java
index fb80bb7a4124..ec6049868863 100644
--- a/platform/util/src/com/intellij/util/messages/impl/MessageBusConnectionImpl.java
+++ b/platform/util/src/com/intellij/util/messages/impl/MessageBusConnectionImpl.java
@@ -58,7 +58,6 @@ public class MessageBusConnectionImpl implements MessageBusConnection {
   }
 
   @Override
-  @SuppressWarnings("unchecked")
   public <L> void subscribe(@NotNull Topic<L> topic) throws IllegalStateException {
     if (myDefaultHandler == null) {
       throw new IllegalStateException("Connection must have default handler installed prior to any anonymous subscriptions. "
@@ -69,6 +68,7 @@ public class MessageBusConnectionImpl implements MessageBusConnection {
                                       topic.getListenerClass() + "', actual: '" + myDefaultHandler.getClass() + "'");
     }
 
+    //noinspection unchecked
     subscribe(topic, (L)myDefaultHandler);
   }
 
@@ -134,7 +134,7 @@ public class MessageBusConnectionImpl implements MessageBusConnection {
     }
   }
 
-  void scheduleMessageDelivery(Message message) {
+  void scheduleMessageDelivery(@NotNull Message message) {
     myPendingMessages.get().offer(message);
   }
 
@@ -142,6 +142,7 @@ public class MessageBusConnectionImpl implements MessageBusConnection {
     return mySubscriptions.toString();
   }
 
+  @NotNull
   MessageBusImpl getBus() {
     return myBus;
   }
diff --git a/platform/util/src/com/intellij/util/messages/impl/MessageBusImpl.java b/platform/util/src/com/intellij/util/messages/impl/MessageBusImpl.java
index 17f3465a6542..131a8cbea7f7 100644
--- a/platform/util/src/com/intellij/util/messages/impl/MessageBusImpl.java
+++ b/platform/util/src/com/intellij/util/messages/impl/MessageBusImpl.java
@@ -383,7 +383,7 @@ public class MessageBusImpl implements MessageBus {
     while (true);
   }
 
-  void notifyOnSubscription(@NotNull MessageBusConnectionImpl connection, @NotNull Topic topic) {
+  void notifyOnSubscription(@NotNull MessageBusConnectionImpl connection, @NotNull Topic<?> topic) {
     checkNotDisposed();
     List<MessageBusConnectionImpl> topicSubscribers = mySubscribers.get(topic);
     if (topicSubscribers == null) {