dfa analysis should be aware that super calls may change fields (IDEA-102126)

java/java-impl/src/com/intellij/codeInspection/dataFlow/value/DfaValueFactory.java

@@ -159,8 +159,8 @@ public class DfaValueFactory {
     if (qualifier == null) {
       return true;
     }
-    if (qualifier instanceof PsiThisExpression){
-      final PsiJavaCodeReferenceElement thisQualifier = ((PsiThisExpression)qualifier).getQualifier();
+    if (qualifier instanceof PsiQualifiedExpression) { //this or super
+      final PsiJavaCodeReferenceElement thisQualifier = ((PsiQualifiedExpression)qualifier).getQualifier();
       if (thisQualifier == null) return true;
       final PsiClass innerMostClass = PsiTreeUtil.getParentOfType(refExpression, PsiClass.class);
       if (innerMostClass == thisQualifier.resolve()) {

java/java-tests/testData/inspection/dataFlow/fixture/SuperCallMayChangeFields.java

@@ -0,0 +1,20 @@
+class Base {
+  void foo() {}
+  void bar() { foo(); }
+}
+
+class Test extends Base {
+  private String string;
+
+  void foo() {
+    string = "";
+  }
+
+  protected void bar() {
+    string = null;
+    super.bar();
+
+    if (string != null)
+      super.bar();
+  }
+}

java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java

@@ -144,6 +144,7 @@ public class DataFlowInspectionTest extends LightCodeInsightFixtureTestCase {
   public void testMutableNullableFieldsTreatment() { doTest(); }
   public void testMutableVolatileNullableFieldsTreatment() { doTest(); }
   public void testMutableNotAnnotatedFieldsTreatment() { doTest(); }
+  public void testSuperCallMayChangeFields() { doTest(); }
 
   public void testMethodCallFlushesField() { doTest(); }
   public void testUnknownFloatMayBeNaN() { doTest(); }