IDEA-63641 Eliminate variable itself from autocomplete list

java/java-impl/src/com/intellij/psi/filters/element/ExcludeSillyAssignment.java

@@ -39,7 +39,12 @@ public class ExcludeSillyAssignment implements ElementFilter {
         final PsiExpression left = ((PsiAssignmentExpression)each).getLExpression();
         if (left instanceof PsiReferenceExpression) {
           final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)left;
-          if (referenceExpression.isQualified()) return true;
+          final PsiElement qualifier = referenceExpression.getQualifier();
+          if (qualifier != null) {
+            if (!(qualifier instanceof PsiThisExpression) || ((PsiThisExpression)qualifier).getQualifier() != null) {
+              return true;
+            }
+          }
 
           return !referenceExpression.isReferenceTo((PsiElement)element);
         }

java/java-tests/testData/codeInsight/completion/smartType/ThisFieldAssignedToItself.java

@@ -0,0 +1,8 @@
+class A {
+    Object field;
+
+    A() {
+        field = 2;
+        this.field = fi<caret>
+    }
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/SmartTypeCompletionTest.java

@@ -961,6 +961,7 @@ public class SmartTypeCompletionTest extends LightFixtureCompletionTestCase {
   public void testWildcardedInstanceof3() throws Throwable { doTest(); }
 
   public void testCheckStaticImportsType() throws Throwable { doAntiTest(); }
+  public void testThisFieldAssignedToItself() throws Throwable { doAntiTest(); }
 
   public void testTypeVariableInstanceOf() throws Throwable {
     configureByTestName();