From 316e41c33b49e1bfbc986eb04882ac2708ed7be6 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Fri, 7 Sep 2012 17:39:30 +0200
Subject: [PATCH] IDEA-90613 Invalid @Nullable processing

---
 .../dataFlow/StandardInstructionVisitor.java  | 19 +++++++++++------
 .../NotEqualsDoesntImplyNotNullity.java       | 21 +++++++++++++++++++
 .../DataFlowInspectionFixtureTest.java        |  1 +
 3 files changed, 35 insertions(+), 6 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/NotEqualsDoesntImplyNotNullity.java

diff --git a/java/java-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java b/java/java-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
index 9c11f3900998..9dd3b2b489c7 100644
--- a/java/java-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
+++ b/java/java-impl/src/com/intellij/codeInspection/dataFlow/StandardInstructionVisitor.java
@@ -274,12 +274,8 @@ public class StandardInstructionVisitor extends InstructionVisitor {
 
         final DfaMemoryState trueCopy = memState.createCopy();
         if (trueCopy.applyCondition(dfaRelation)) {
-          if (dfaLeft instanceof DfaVariableValue && dfaRight instanceof DfaVariableValue) {
-            if (trueCopy.isNotNull((DfaVariableValue)dfaLeft)) {
-              trueCopy.applyCondition(relationFactory.create(dfaRight, factory.getConstFactory().getNull(), JavaTokenType.EQEQ, true));
-            } else if (trueCopy.isNotNull((DfaVariableValue)dfaRight)) {
-              trueCopy.applyCondition(relationFactory.create(dfaLeft, factory.getConstFactory().getNull(), JavaTokenType.EQEQ, true));
-            }
+          if (!dfaRelation.isNegated()) {
+            handleEqualVariables(dfaRight, dfaLeft, factory, trueCopy);
           }
           trueCopy.push(factory.getConstFactory().getTrue());
           instruction.setTrueReachable();
@@ -335,6 +331,17 @@ public class StandardInstructionVisitor extends InstructionVisitor {
     return nextInstruction(instruction, runner, memState);
   }
 
+  private static void handleEqualVariables(DfaValue var1, DfaValue var2, DfaValueFactory factory, DfaMemoryState state) {
+    if (!(var2 instanceof DfaVariableValue) || !(var1 instanceof DfaVariableValue)) {
+      return;
+    }
+
+    DfaValue nowNotNull = state.isNotNull((DfaVariableValue)var2) ? var1 : state.isNotNull((DfaVariableValue)var1) ? var2 : null;
+    if (nowNotNull != null) {
+      state.applyCondition(factory.getRelationFactory().create(nowNotNull, factory.getConstFactory().getNull(), JavaTokenType.EQEQ, true));
+    }
+  }
+
   public boolean isInstanceofRedundant(InstanceofInstruction instruction) {
     return !myUsefulInstanceofs.contains(instruction) && !instruction.isConditionConst() && myReachable.contains(instruction);
   }
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/NotEqualsDoesntImplyNotNullity.java b/java/java-tests/testData/inspection/dataFlow/fixture/NotEqualsDoesntImplyNotNullity.java
new file mode 100644
index 000000000000..e74585c3a198
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/NotEqualsDoesntImplyNotNullity.java
@@ -0,0 +1,21 @@
+import org.jetbrains.annotations.Nullable;
+class TestIDEAWarn {
+  void test(java.util.Map<Object, Object> values) {
+    boolean condition = false;
+    Object target = getTarget();
+    for (Object o : values.values()) {
+      if (o != null && o != target) {
+        condition = true;
+      }
+    }
+    if (!condition || target == null) {
+      System.out.println(target);
+    }
+  }
+
+  @Nullable
+  public Object getTarget() {
+    return null;
+  }
+
+}
diff --git a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionFixtureTest.java b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionFixtureTest.java
index 4412631e42eb..67b9ed456daa 100644
--- a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionFixtureTest.java
+++ b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionFixtureTest.java
@@ -72,5 +72,6 @@ public class DataFlowInspectionFixtureTest extends JavaCodeInsightFixtureTestCas
 
   public void testEqualsNotNull() throws Throwable { doTest(); }
   public void testVisitFinallyOnce() throws Throwable { doTest(); }
+  public void testNotEqualsDoesntImplyNotNullity() throws Throwable { doTest(); }
 
 }