From 7253845d5f0fc3663414d889e97aed2198a44a23 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Tue, 17 Apr 2018 10:52:38 +0700
Subject: [PATCH] DfaMemoryStateImpl: fix sentinel handling

---
 .../dataFlow/DfaMemoryStateImpl.java              | 15 ++++++++-------
 .../dataFlow/fixture/StreamInlining.java          |  3 ++-
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
index 231fa632e906..a440db821a36 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java
@@ -789,9 +789,15 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
   private boolean applyRelationCondition(@NotNull DfaRelationValue dfaRelation) {
     DfaValue dfaLeft = dfaRelation.getLeftOperand();
     DfaValue dfaRight = dfaRelation.getRightOperand();
-    if (dfaLeft instanceof DfaUnknownValue || dfaRight instanceof DfaUnknownValue) return true;
     RelationType relationType = dfaRelation.getRelation();
 
+    DfaConstValue sentinel = getFactory().getConstFactory().getSentinel();
+    if (dfaLeft == sentinel || dfaRight == sentinel) {
+      assert relationType == RelationType.EQ || relationType == RelationType.NE;
+      return (dfaLeft == dfaRight) == (relationType == RelationType.EQ);
+    }
+    if (dfaLeft instanceof DfaUnknownValue || dfaRight instanceof DfaUnknownValue) return true;
+
     LongRangeSet left = getValueFact(dfaLeft, DfaFactType.RANGE);
     LongRangeSet right = getValueFact(dfaRight, DfaFactType.RANGE);
 
@@ -896,11 +902,6 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
       return !isNegated || (dfaLeft instanceof DfaVariableValue && ((DfaVariableValue)dfaLeft).containsCalls());
     }
 
-    DfaConstValue sentinel = getFactory().getConstFactory().getSentinel();
-    if (dfaLeft == sentinel || dfaRight == sentinel) {
-      return isNegated;
-    }
-
     if (isNull(dfaLeft) && isNotNull(dfaRight) || isNull(dfaRight) && isNotNull(dfaLeft)) {
       return isNegated;
     }
@@ -1114,7 +1115,7 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
   public <T> void forceVariableFact(@NotNull DfaVariableValue var, @NotNull DfaFactType<T> factType, @Nullable T value) {
     if (isUnknownState(var)) return;
     DfaVariableState state = getVariableState(var);
-    flushVariable(var);
+    removeEquivalenceRelations(var);
     setVariableState(var, state.withFact(factType, value));
     updateEqClassesByState(var);
   }
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/StreamInlining.java b/java/java-tests/testData/inspection/dataFlow/fixture/StreamInlining.java
index e19052695270..30fd35113251 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/StreamInlining.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/StreamInlining.java
@@ -126,7 +126,8 @@ public class StreamInlining {
   boolean flatMap(List<String> list, List<List<String>> ll) {
     System.out.println(ll.stream().flatMap(l -> l.stream()).count());
     return list.stream().map(s -> s.isEmpty() ? null : s)
-      .flatMap(s -> Stream.of(s, s.<warning descr="Method invocation 'trim' may produce 'java.lang.NullPointerException'">trim</warning>()).filter(r -> r != null))
+               .flatMap(s -> Stream.of(s, s.<warning descr="Method invocation 'trim' may produce 'java.lang.NullPointerException'">trim</warning>())
+                    .filter(r -> <warning descr="Condition 'r != null' is always 'true'">r != null</warning>))
       .anyMatch(x -> <warning descr="Condition 'x == null' is always 'false'">x == null</warning>);
   }