IDEA-85760 completion menu shouldn't offer null where it makes no sense

java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionData.java

@@ -148,7 +148,8 @@ public class JavaCompletionData extends JavaAwareCompletionData{
       not(
         or(psiElement(PsiTypeCastExpression.class),
            psiElement(PsiSwitchLabelStatement.class),
-           psiElement(PsiExpressionStatement.class)
+           psiElement(PsiExpressionStatement.class),
+           psiElement(PsiPrefixExpression.class)
         )
       )
     )),

java/java-tests/testData/codeInsight/completion/normal/IncNull.java

@@ -0,0 +1,5 @@
+class Foo {
+    {
+        ++nu<caret>
+    }
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy

@@ -539,6 +539,7 @@ public class ListUtils {
   }
 
   public void testNoThisInComment() throws Throwable { doAntiTest() }
+  public void testIncNull() throws Throwable { doAntiTest() }
 
   public void testLastExpressionInFor() throws Throwable { doTest(); }