dfa: if a variable is not nullable-enabled, don't make it such

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java

@@ -79,7 +79,7 @@ class StateMerger {
           for (DfaVariableValue unknownVar : removedState.getUnknownVariables()) {
             copy.doFlush(unknownVar, true);
           }
-          if (removedState.isNull(var)) {
+          if (removedState.getVariableState(var).isNullable()) {
             copy.setVariableState(var, copy.getVariableState(var).withNullability(Nullness.NULLABLE));
           }
         }

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

@@ -0,0 +1,18 @@
+import java.io.File;
+
+class Some {
+  private void findRepository(File file, boolean b) {
+    System.out.println(file.getName());
+    if (b) {
+      File parent = file;
+      while (parent != null) {
+        parent = parent.getParentFile();
+      }
+      System.out.println(<warning descr="Method invocation 'parent.getName()' may produce 'java.lang.NullPointerException'">parent.getName()</warning>);
+    }
+    System.out.println(file.getName());
+  }
+
+}
+
+

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

@@ -302,6 +302,7 @@ public class DataFlowInspectionTest extends LightCodeInsightFixtureTestCase {
   public void testManySequentialIfsNotComplex() { doTest(); }
   public void testLongDisjunctionsNotComplex() { doTest(); }
   public void testWhileNotComplex() { doTest(); }
+  public void testVariablesDiverge() { doTest(); }
   
   public void _testNullCheckBeforeInstanceof() { doTest(); }
 }