ConvertFieldToAtomicIntention#isAvailable: check that getVariable() actually returns something

Should fix EA-107511 - assert: ConvertFieldToAtomicIntention.invoke

java/typeMigration/src/com/intellij/refactoring/typeMigration/intentions/ConvertFieldToAtomicIntention.java

@@ -148,7 +148,6 @@ public class ConvertFieldToAtomicIntention extends PsiElementBaseIntentionAction
           else if (var instanceof PsiField) {
             ((PsiField)var).setInitializer(newInitializer);
           }
-          JavaCodeStyleManager.getInstance(var.getProject()).shortenClassReferences(var.getInitializer());
         }
 
         modifierList.setModifierProperty(PsiModifier.FINAL, true);
@@ -219,7 +218,7 @@ public class ConvertFieldToAtomicIntention extends PsiElementBaseIntentionAction
 
     @Override
     public boolean isAvailable(@NotNull Project project, Editor editor, @NotNull PsiElement element) {
-      return myContext.isValid();
+      return getVariable(element) != null;
     }
 
     @Override

java/typeMigration/testData/intentions/atomic/afterInLambdasAtWrite.java

@@ -0,0 +1,21 @@
+// "Convert to atomic" "true"
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.*;
+
+public class InLambdas
+{
+  public void test()
+  {
+    AtomicInteger x = new AtomicInteger();
+    // Also active at write point if it causes a compilation error
+    Runnable r1 = () -> x.getAndIncrement();
+    Runnable r2 = () -> x.addAndGet(2);
+    Runnable r3 = () -> x.updateAndGet(v -> v * 2);
+    Runnable r4 = () -> x.set(5);
+    System.out.println(x.updateAndGet(v -> v / 3));
+    IntSupplier s = () -> {
+      return x.updateAndGet(v -> v * 2);
+    };
+  }
+}

java/typeMigration/testData/intentions/atomic/beforeInLambdasAtWrite.java

@@ -0,0 +1,20 @@
+// "Convert to atomic" "true"
+
+import java.util.function.*;
+
+public class InLambdas
+{
+  public void test()
+  {
+    int x = 0;
+    // Also active at write point if it causes a compilation error
+    Runnable r1 = () -> <caret>x++;
+    Runnable r2 = () -> x+=2;
+    Runnable r3 = () -> x*=2;
+    Runnable r4 = () -> x = 5;
+    System.out.println(x /= 3);
+    IntSupplier s = () -> {
+      return x *= 2;
+    };
+  }
+}