method call should always flush fields (IDEA-93168)

java/java-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryState.java

@@ -60,6 +60,4 @@ public interface DfaMemoryState {
   boolean isNotNull(DfaVariableValue dfaVar);
 
   void flushVariableOutOfScope(DfaVariableValue variable);
-
-  void fieldReferenced();
 }

java/java-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java

@@ -50,7 +50,6 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
   private TIntStack myOffsetStack;
   private TLongHashSet myDistinctClasses;
   private THashMap<DfaVariableValue,DfaVariableState> myVariableStates;
-  private boolean myHasDirtyFields = true;
 
   public DfaMemoryStateImpl(final DfaValueFactory factory) {
     myFactory = factory;
@@ -80,7 +79,6 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
     newState.myStateSize = myStateSize;
     newState.myVariableStates = new THashMap<DfaVariableValue, DfaVariableState>();
     newState.myOffsetStack = new TIntStack(myOffsetStack);
-    newState.myHasDirtyFields = myHasDirtyFields;
 
     for (int i = 0; i < myEqClasses.size(); i++) {
       SortedIntSet aClass = myEqClasses.get(i);
@@ -111,7 +109,6 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
     if (!myStack.equals(that.myStack)) return false;
     if (!myOffsetStack.equals(that.myOffsetStack)) return false;
     if (!myVariableStates.equals(that.myVariableStates)) return false;
-    if (myHasDirtyFields != that.myHasDirtyFields) return false;
 
     int[] permutation = getPermutationToSortedState();
     int[] thatPermutation = that.getPermutationToSortedState();
@@ -494,11 +491,6 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
     myDistinctClasses.add(createPair(c1Index, c2Index));
   }
 
-  @Override
-  public void fieldReferenced() {
-    myHasDirtyFields = true;
-  }
-
   public boolean isNull(DfaValue dfaValue) {
     if (dfaValue instanceof DfaNotNullValue) return false;
 
@@ -773,12 +765,11 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
   }
 
   public void flushFields(DataFlowRunner runner) {
-    if (!myHasDirtyFields) return;
-
-    myHasDirtyFields = false;
     for (DfaVariableValue field : runner.getFields()) {
-      flushVariable(field);
-      getVariableState(field).setNullable(false);
+      if (myVariableStates.containsKey(field) || getEqClassIndex(field) >= 0) {
+        flushVariable(field);
+        getVariableState(field).setNullable(false);
+      }
     }
   }
 

java/java-impl/src/com/intellij/codeInspection/dataFlow/InstructionVisitor.java

@@ -150,9 +150,6 @@ public abstract class InstructionVisitor {
   }
 
   public DfaInstructionState[] visitPush(PushInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
-    if (instruction.isFieldReference()) {
-      memState.fieldReferenced();
-    }
     memState.push(instruction.getValue());
     return nextInstruction(instruction, runner, memState);
   }

java/java-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java

@@ -146,7 +146,6 @@ public class StandardInstructionVisitor extends InstructionVisitor {
 
   @Override
   public DfaInstructionState[] visitFieldReference(FieldReferenceInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
-    memState.fieldReferenced();
     final DfaValue qualifier = memState.pop();
     if (instruction.getExpression().isPhysical() && !memState.applyNotNull(qualifier)) {
       onInstructionProducesNPE(instruction);

java/java-impl/src/com/intellij/codeInspection/dataFlow/instructions/PushInstruction.java

@@ -62,8 +62,4 @@ public class PushInstruction extends Instruction {
   public String toString() {
     return "PUSH " + myValue;
   }
-
-  public boolean isFieldReference() {
-    return myPlace instanceof PsiReferenceExpression && ((PsiReferenceExpression)myPlace).resolve() instanceof PsiField;
-  }
 }

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

@@ -0,0 +1,21 @@
+import org.jetbrains.annotations.Nullable;
+
+class Fun {
+  @Nullable
+  private Object foo;
+
+  public Fun() {
+    foo = new Object();
+    makeMagic();
+
+    if (null == foo) {
+      System.out.println("hello");
+    }
+
+  }
+
+  private void makeMagic() {
+    foo = null;
+  }
+
+}

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

@@ -136,4 +136,6 @@ public class DataFlowInspectionFixtureTest extends JavaCodeInsightFixtureTestCas
   public void _testMutableVolatileNullableFieldsTreatment() { doTest(); }
   public void testMutableNotAnnotatedFieldsTreatment() { doTest(); }
 
+  public void testMethodCallFlushesField() { doTest(); }
+
 }