dfa: treat different constants with same values as same (IDEA-121837)

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

@@ -89,11 +89,10 @@ public class DfaConstValue extends DfaValue {
       if (TypeConversionUtil.isNumericType(type) && !TypeConversionUtil.isFloatOrDoubleType(type)) {
         value = TypeConversionUtil.computeCastTo(value, PsiType.LONG);
       }
-      Object key = constant != null ? constant : value;
-      DfaConstValue instance = myValues.get(key);
+      DfaConstValue instance = myValues.get(value);
       if (instance == null) {
         instance = new DfaConstValue(value, myFactory, constant);
-        myValues.put(key, instance);
+        myValues.put(value, instance);
       }
 
       return instance;

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

@@ -0,0 +1,38 @@
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.Nullable;
+
+class Doo {
+
+  static final int TYPE_1 = 20;
+  static final int TYPE_2 = 20;
+
+  public static void failedSecondCondition(int type) {
+    if(type != TYPE_1) {
+      return;
+    }
+
+    if(<warning descr="Condition 'type != TYPE_2' is always 'false'">type != TYPE_2</warning>) {
+      System.out.println();
+    }
+  }
+
+
+}
+
+class Doo2 {
+
+  static final int TYPE_1 = 200;
+  static final int TYPE_2 = 200;
+
+  public static void failedSecondCondition(int type) {
+    if(type != TYPE_1) {
+      return;
+    }
+
+    if(<warning descr="Condition 'type != TYPE_2' is always 'false'">type != TYPE_2</warning>) {
+      System.out.println();
+    }
+  }
+
+
+}

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

@@ -309,6 +309,8 @@ public class DataFlowInspectionTest extends LightCodeInsightFixtureTestCase {
   public void testUnusedCallDoesNotMakeUnknown() { doTest(); }
   public void testGettersAndPureNoFlushing() { doTest(); }
 
+  public void testSameComparisonTwice() { doTest(); }
+
   public void testParametersAreNonnullByDefault() {
     myFixture.addClass("package javax.annotation; public @interface ParametersAreNonnullByDefault {}");
     myFixture.addClass("package javax.annotation; public @interface ParametersAreNullableByDefault {}");