IDEA-160635 'Condition always true' inspection sometimes incorrect when inner class access final field

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaPsiUtil.java

@@ -20,7 +20,6 @@ import com.intellij.codeInsight.NullableNotNullManager;
 import com.intellij.codeInspection.dataFlow.instructions.Instruction;
 import com.intellij.codeInspection.dataFlow.instructions.MethodCallInstruction;
 import com.intellij.codeInspection.dataFlow.instructions.ReturnInstruction;
-import com.intellij.codeInspection.dataFlow.value.DfaValueFactory;
 import com.intellij.lang.java.JavaLanguage;
 import com.intellij.openapi.util.Ref;
 import com.intellij.patterns.PsiJavaPatterns;
@@ -32,6 +31,7 @@ import com.intellij.psi.util.*;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.NullableFunction;
 import com.intellij.util.containers.ContainerUtil;
+import com.intellij.util.containers.JBIterable;
 import com.intellij.util.containers.MultiMap;
 import com.intellij.util.containers.Stack;
 import org.jetbrains.annotations.NotNull;
@@ -220,21 +220,34 @@ public class DfaPsiUtil {
             PsiCall call = ((MethodCallInstruction)instruction).getCallExpression();
             if (call == null) return false;
 
-            if (call instanceof PsiMethodCallExpression &&
-                DfaValueFactory.isEffectivelyUnqualified(((PsiMethodCallExpression)call).getMethodExpression())) {
+            if (call instanceof PsiNewExpression && canAccessFields((PsiExpression)call)) {
               return true;
             }
 
+            if (call instanceof PsiMethodCallExpression) {
+              PsiExpression qualifier = ((PsiMethodCallExpression)call).getMethodExpression().getQualifierExpression();
+              if (qualifier == null || canAccessFields(qualifier)) {
+                return true;
+              }
+            }
+
             PsiExpressionList argumentList = call.getArgumentList();
             if (argumentList != null) {
               for (PsiExpression expression : argumentList.getExpressions()) {
-                if (expression instanceof PsiThisExpression) return true;
+                if (canAccessFields(expression)) return true;
               }
             }
 
             return false;
           }
 
+          private boolean canAccessFields(PsiExpression expression) {
+            PsiClass type = PsiUtil.resolveClassInClassTypeOnly(expression.getType());
+            JBIterable<PsiClass> typeContainers =
+              JBIterable.generate(type, PsiClass::getContainingClass).takeWhile(c -> !c.hasModifierProperty(PsiModifier.STATIC));
+            return typeContainers.contains(containingClass);
+          }
+
           @NotNull
           @Override
           protected DfaInstructionState[] acceptInstruction(@NotNull InstructionVisitor visitor, @NotNull DfaInstructionState instructionState) {

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaVariableValue.java

@@ -189,30 +189,26 @@ public class DfaVariableValue extends DfaValue {
     }
 
     if (var instanceof PsiField && DfaPsiUtil.isFinalField((PsiVariable)var) && myFactory.isHonorFieldInitializers()) {
+      PsiExpression initializer = ((PsiField)var).getInitializer();
+      if (initializer != null) {
+        return getFieldInitializerNullness(initializer);
+      }
+
       List<PsiExpression> initializers = DfaPsiUtil.findAllConstructorInitializers((PsiField)var);
       if (initializers.isEmpty()) {
         return defaultNullability;
       }
 
-      boolean hasUnknowns = false;
       for (PsiExpression expression : initializers) {
-        Nullness nullness = getFieldInitializerNullness(expression);
-        if (nullness == Nullness.NULLABLE) {
+        if (getFieldInitializerNullness(expression) == Nullness.NULLABLE) {
           return Nullness.NULLABLE;
         }
-        if (nullness == Nullness.UNKNOWN) {
-          hasUnknowns = true;
-        }
       }
-      
-      if (hasUnknowns) {
-        if (DfaPsiUtil.isInitializedNotNull((PsiField)var)) {
-          return Nullness.NOT_NULL;
-        }
-        return defaultNullability;
+
+      if (DfaPsiUtil.isInitializedNotNull((PsiField)var)) {
+        return Nullness.NOT_NULL;
       }
-      
-      return Nullness.NOT_NULL;
+      return defaultNullability;
     }
 
     return defaultNullability;
@@ -223,11 +219,11 @@ public class DfaVariableValue extends DfaValue {
     if (expression instanceof PsiNewExpression || expression instanceof PsiLiteralExpression || expression instanceof PsiPolyadicExpression) return Nullness.NOT_NULL;
     if (expression instanceof PsiReferenceExpression) {
       PsiElement target = ((PsiReferenceExpression)expression).resolve();
-      return DfaPsiUtil.getElementNullability(null, (PsiModifierListOwner)target);
+      return DfaPsiUtil.getElementNullability(expression.getType(), (PsiModifierListOwner)target);
     }
     if (expression instanceof PsiMethodCallExpression) {
       PsiMethod method = ((PsiMethodCallExpression)expression).resolveMethod();
-      return method != null ? DfaPsiUtil.getElementNullability(null, method) : Nullness.UNKNOWN;
+      return method != null ? DfaPsiUtil.getElementNullability(expression.getType(), method) : Nullness.UNKNOWN;
     }
     return Nullness.UNKNOWN;
   }

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

@@ -0,0 +1,20 @@
+class FailingNonNull {
+  private final String nullable;
+
+  public FailingNonNull() {
+    Inner inner = new Inner();
+    inner.doNullableStuff();
+    nullable = "now non-null";
+  }
+
+  private class Inner{
+    public void doNullableStuff() {
+      if (nullable !=null) { //Condition 'nullable!=null' is always 'true'
+        System.out.println(nullable.length());
+      }
+    }
+  }
+  public static void main(String[] args) {
+    new FailingNonNull();
+  }
+}

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

@@ -193,6 +193,7 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
   public void testRememberLocalTransientFieldState() { doTest(); }
   public void testFinalFieldDuringInitialization() { doTest(); }
   public void testFinalFieldDuringSuperInitialization() { doTest(); }
+  public void testFinalFieldInCallBeforeInitialization() { doTest(); }
   public void testFinalFieldInConstructorAnonymous() { doTest(); }
 
   public void testFinalFieldNotDuringInitialization() {