From 14f7907d29f4e820c92b8ce8a5d3cff6322632ce Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Fri, 10 Jul 2020 19:46:02 +0700
Subject: [PATCH] Better fix for IDEA-245423 Incorrect "Condition X covered by
 subsequent condition Y" warning

Review ID: IDEA-CR-64866

GitOrigin-RevId: 7d2e5c40ce9d010975583f6fecc14ac6aff2a2e1
---
 .../codeInspection/dataFlow/value/DfaCondition.java | 13 +++++++------
 .../dataFlow/value/DfaValueFactory.java             |  5 +----
 .../ConditionCoveredByFurtherCondition.java         | 11 +++++++++++
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaCondition.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaCondition.java
index c8e8b82d318d..1f4bc8c73766 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaCondition.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaCondition.java
@@ -2,10 +2,7 @@
 package com.intellij.codeInspection.dataFlow.value;
 
 import com.intellij.codeInspection.dataFlow.DfaUtil;
-import com.intellij.codeInspection.dataFlow.types.DfConstantType;
-import com.intellij.codeInspection.dataFlow.types.DfIntegralType;
-import com.intellij.codeInspection.dataFlow.types.DfType;
-import com.intellij.codeInspection.dataFlow.types.DfTypes;
+import com.intellij.codeInspection.dataFlow.types.*;
 import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -106,12 +103,12 @@ public abstract class DfaCondition {
                                !DfaUtil.isNaN(((DfConstantType<?>)leftType).getValue()) ^
                                relationType == RelationType.EQ);
           }
-          if (!rightType.isSuperType(leftType)) {
+          if (!couldBeEqualToConstant(rightType, leftType)) {
             return fromBoolean(relationType == RelationType.NE);
           }
         }
         else if (rightType instanceof DfConstantType) {
-          if (!leftType.isSuperType(rightType)) {
+          if (!couldBeEqualToConstant(leftType, rightType)) {
             return fromBoolean(relationType == RelationType.NE);
           }
         }
@@ -141,5 +138,9 @@ public abstract class DfaCondition {
 
       return null;
     }
+
+    private static boolean couldBeEqualToConstant(DfType type, DfType constantType) {
+      return (type instanceof DfReferenceType ? ((DfReferenceType)type).dropTypeConstraint() : type).isSuperType(constantType);
+    }
   }
 }
diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaValueFactory.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaValueFactory.java
index 083d18897036..bd7146813455 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaValueFactory.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaValueFactory.java
@@ -179,10 +179,7 @@ public class DfaValueFactory {
         return getNull();
       }
       if (variable instanceof PsiField && variable.hasModifierProperty(PsiModifier.STATIC) && ExpressionUtils.isNewObject(initializer)) {
-        PsiType initializerType = initializer.getType();
-        if (initializerType != null) {
-          return getConstant(variable, initializerType);
-        }
+        return getConstant(variable, type);
       }
       return null;
     }
diff --git a/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/condition_covered_by_further_condition/ConditionCoveredByFurtherCondition.java b/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/condition_covered_by_further_condition/ConditionCoveredByFurtherCondition.java
index fee8a6070a84..e6c32d62ca4d 100644
--- a/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/condition_covered_by_further_condition/ConditionCoveredByFurtherCondition.java
+++ b/plugins/InspectionGadgets/test/com/siyeh/igtest/controlflow/condition_covered_by_further_condition/ConditionCoveredByFurtherCondition.java
@@ -9,6 +9,17 @@ public class ConditionCoveredByFurtherCondition {
         public void m() {
             if (this == C1 || this == C2) { /* ...*/ }
         }
+        
+        public static final Object C3 = getC();
+        public static final Object C4 = getC();
+        
+        public void m2() {
+            if (this == C3 || this == C4) {}
+        }
+        
+        private static Object getC() {
+            return new C();
+        }
     }
     
     public void testInstanceOf(Object arg) {