From ad22cd9a7473da2e37f14b7734352fdf29a91e92 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Wed, 21 Apr 2021 11:32:36 +0700
Subject: [PATCH] [java-dfa] Fix ephemeral states on comparison

GitOrigin-RevId: cd7fde86062bcda7145dae7b98c661a64fbccb9d
---
 .../dataFlow/DfaMemoryStateImpl.java               | 14 +++++++-------
 .../fixture/UnknownComparedToNullable.java         | 12 ++++++++++++
 .../codeInspection/DataFlowInspectionTest.java     |  1 +
 3 files changed, 20 insertions(+), 7 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/UnknownComparedToNullable.java

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 e18fef1709fe..aa2adf53a4af 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
@@ -715,6 +715,11 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
 
     if (DfaTypeValue.isUnknown(dfaLeft) || DfaTypeValue.isUnknown(dfaRight)) return true;
 
+    if (relationType == RelationType.EQ && dfaLeft instanceof DfaVariableValue && dfaRight instanceof DfaVariableValue) {
+      checkEphemeral(dfaLeft, dfaRight);
+      checkEphemeral(dfaRight, dfaLeft);
+    }
+
     DfType leftType = getDfType(dfaLeft);
     DfType rightType = getDfType(dfaRight);
 
@@ -877,13 +882,8 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
       return true;
     }
 
-    if (type == RelationType.EQ) {
-      if (dfaLeft instanceof DfaVariableValue && dfaRight instanceof DfaVariableValue) {
-        checkEphemeral(dfaLeft, dfaRight);
-        checkEphemeral(dfaRight, dfaLeft);
-      }
-      if (!applySpecialFieldEquivalence(dfaLeft, dfaRight)) return false;
-    }
+    if (type == RelationType.EQ && !applySpecialFieldEquivalence(dfaLeft, dfaRight)) return false;
+
     if (dfaLeft instanceof DfaVariableValue && dfaRight instanceof DfaVariableValue && !isNegated) {
       if (!equalizeTypesOnGetClass((DfaVariableValue)dfaLeft, (DfaVariableValue)dfaRight)) {
         return false;
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/UnknownComparedToNullable.java b/java/java-tests/testData/inspection/dataFlow/fixture/UnknownComparedToNullable.java
new file mode 100644
index 000000000000..91d30f81a856
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/UnknownComparedToNullable.java
@@ -0,0 +1,12 @@
+import java.util.Set;
+
+public class UnknownComparedToNullable {
+  native Object getObject(int x);
+
+  void test(int val) {
+    Object s1 = val < 0 ? null : getObject(val * 2);
+    Object s2 = getObject(val);
+    if (s1 != s2) {}
+    System.out.println(s2.hashCode());
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
index 50a9171314ce..29d94fcfa3fc 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
@@ -696,4 +696,5 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
   public void testCollectionViewsSize() { doTest(); }
   public void testFlushedNullableOnUnknownCall() { doTest(); }
   public void testBoxedDivisionComparison() { doTest(); }
+  public void testUnknownComparedToNullable() { doTest(); }
 }