IDEA-175296 Uncaught 'condition is always false' with interface constant

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

@@ -135,7 +135,7 @@ public class DfaExpressionFactory {
         if (constValue != null) return constValue;
       }
 
-      if (DfaValueFactory.isEffectivelyUnqualified(refExpr)) {
+      if (DfaValueFactory.isEffectivelyUnqualified(refExpr) || isStaticFinalConstantWithoutInitializationHacks(var)) {
         if (isFieldDereferenceBeforeInitialization(refExpr)) {
           return myFactory.getConstFactory().getNull();
         }
@@ -153,6 +153,16 @@ public class DfaExpressionFactory {
     return myFactory.createTypeValue(type, DfaPsiUtil.getElementNullability(type, var));
   }
 
+  private static boolean isStaticFinalConstantWithoutInitializationHacks(PsiModifierListOwner var) {
+    if (var instanceof PsiField && var.hasModifierProperty(PsiModifier.FINAL) && var.hasModifierProperty(PsiModifier.STATIC)) {
+      PsiClass containingClass = ((PsiField)var).getContainingClass();
+      if (containingClass != null && !System.class.getName().equals(containingClass.getQualifiedName())) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   private static boolean isFieldDereferenceBeforeInitialization(PsiReferenceExpression ref) {
     PsiField placeField = PsiTreeUtil.getParentOfType(ref, PsiField.class, true, PsiClass.class, PsiLambdaExpression.class);
     if (placeField == null) return false;

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

@@ -0,0 +1,10 @@
+interface I {
+  Object CONST = new Object();
+}
+
+class C {
+  void foo(Object o) {
+    if (o == I.CONST) return;
+    if (<warning descr="Condition 'o != I.CONST' is always 'true'">o != I.CONST</warning>) return;
+  }
+}

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

@@ -483,6 +483,8 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
     checkIntentionResult("Remove 'for' statement");
   }
 
+  public void testUsingInterfaceConstant() { doTest();}
+
   //https://youtrack.jetbrains.com/issue/IDEA-162184
   public void testNullLiteralAndInferredMethodContract() {
     doTest();