IDEA-119663 false positive Constant conditions & exceptions: "Argument ... might be null"

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

@@ -0,0 +1,46 @@
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class TestInspection {
+
+  private static class StringWrapper {
+    private String inner = null;
+
+    @Nullable
+    public String getString() {
+      return inner;
+    }
+  }
+
+  @NotNull
+  private final StringWrapper wrapper;
+
+  @Nullable
+  private String string = null;
+
+  public TestInspection() {
+    wrapper = new StringWrapper();
+  }
+
+  public void doTest() {
+    if (this.wrapper.getString() != null) {
+      doSomething(this.wrapper.getString());
+    }
+    if (this.wrapper.getString() != null) {
+      doSomething(wrapper.getString());
+    }
+    if (wrapper.getString() != null) {
+      doSomething(this.wrapper.getString());
+    }
+    if (wrapper.getString() != null) {
+      doSomething(wrapper.getString());
+    }
+    if (this.string != null) {
+      doSomething(this.string);
+    }
+  }
+
+  private void doSomething(@NotNull String s) {
+    //...
+  }
+}

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

@@ -104,6 +104,7 @@ public class DataFlowInspectionTest extends LightCodeInsightFixtureTestCase {
   public void testChainedFinalFieldAccessorsDfa() throws Throwable { doTest(); }
   public void testAccessorPlusMutator() throws Throwable { doTest(); }
   public void testClosureVariableField() throws Throwable { doTest(); }
+  public void testOptionalThis() { doTest(); }
 
   public void testAssigningNullableToNotNull() throws Throwable { doTest(); }
   public void testAssigningUnknownToNullable() throws Throwable { doTest(); }