From dea8248bfe7bea67b12fbee9718738e1136dbfa7 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Thu, 26 Sep 2013 17:41:52 +0200
Subject: [PATCH] dfa: if a variable is not nullable-enabled, don't make it
 such

---
 .../codeInspection/dataFlow/StateMerger.java   |  2 +-
 .../dataFlow/fixture/VariablesDiverge.java     | 18 ++++++++++++++++++
 .../codeInspection/DataFlowInspectionTest.java |  1 +
 3 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/VariablesDiverge.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
index e886dde637a0..658b2d2123ed 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
+++ b/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));
           }
         }
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/VariablesDiverge.java b/java/java-tests/testData/inspection/dataFlow/fixture/VariablesDiverge.java
new file mode 100644
index 000000000000..f07fffb6a8a1
--- /dev/null
+++ b/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());
+  }
+
+}
+
+
diff --git a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
index cc9dee3d26aa..55dd5cce11e1 100644
--- a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
+++ b/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(); }
 }