From a03fffe024d921d08cb884f58c953e8dbd72ea3c Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Mon, 27 Mar 2017 13:18:00 +0700
Subject: [PATCH] DFA Optional.orElse handling improved (splitting states)

---
 .../dataFlow/StandardInstructionVisitor.java           | 10 ++++++----
 .../inspection/dataFlow/fixture/OptionalOrElse.java    |  7 +++++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
index 06a15d328efa..ed0a7cfefab2 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
@@ -287,10 +287,12 @@ public class StandardInstructionVisitor extends InstructionVisitor {
               result = argValues[0];
               break;
             case UNSURE:
-              Nullness nullness =
-                memState.isNotNull(argValues[0]) ? Nullness.NOT_NULL : memState.isNull(argValues[0]) ? Nullness.NULLABLE : Nullness.UNKNOWN;
-              result = runner.getFactory().createTypeValue(instruction.getResultType(), nullness);
-              break;
+              DfaMemoryState falseState = memState.createCopy();
+              memState.push(runner.getFactory().createTypeValue(instruction.getResultType(), Nullness.NOT_NULL));
+              memState.applyIsPresentCheck(true, qualifier);
+              falseState.push(argValues[0]);
+              falseState.applyIsPresentCheck(false, qualifier);
+              return Arrays.asList(memState, falseState);
           }
         }
         break;
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/OptionalOrElse.java b/java/java-tests/testData/inspection/dataFlow/fixture/OptionalOrElse.java
index 8fa53bc5e1dc..dfe45c5fde94 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/OptionalOrElse.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/OptionalOrElse.java
@@ -42,4 +42,11 @@ class OptionalOrElse {
       return "";
     }
   }
+
+  void isPresentCheck(Optional<String> opt) {
+    String result = opt.orElse(null);
+    if(<warning descr="Condition 'result == null && opt.isPresent()' is always 'false'">result == null && <warning descr="Condition 'opt.isPresent()' is always 'false' when reached">opt.isPresent()</warning></warning>) {
+      System.out.println("Impossible");
+    }
+  }
 }
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