IDEA-89654 Incorrect control flow warning with @Nullable

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

@@ -0,0 +1,13 @@
+import org.jetbrains.annotations.*;
+class TestIDEAWarn {
+  void method(@Nullable MyEnum e) {
+    if (e != MyEnum.foo) {return;}
+    System.out.println(e.hashCode());
+  }
+  void method2(@Nullable MyEnum e) {
+    if (e == MyEnum.foo) {
+      System.out.println(e.hashCode());
+    }
+  }
+}
+enum MyEnum { foo, bar }

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

@@ -73,5 +73,6 @@ public class DataFlowInspectionFixtureTest extends JavaCodeInsightFixtureTestCas
   public void testEqualsNotNull() throws Throwable { doTest(); }
   public void testVisitFinallyOnce() throws Throwable { doTest(); }
   public void testNotEqualsDoesntImplyNotNullity() throws Throwable { doTest(); }
+  public void testEqualsEnumConstant() throws Throwable { doTest(); }
 
 }