From cde4e9cab29d193a9f999d977a790e8b157ea32b Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Mon, 12 Oct 2020 16:35:46 +0700
Subject: [PATCH] [java-dfa] Properly cast primitive type in
 getAdvancedExpressionDfaValue

Fixes IDEA-252586 Wrong 'condition is always true' when element of double array is implicitly converted from int

GitOrigin-RevId: 36cf865d5d9d88c14d2f3236a3d068555f7ca216
---
 .../dataFlow/value/DfaExpressionFactory.java           | 10 ++++++++++
 .../inspection/dataFlow/fixture/DoubleArrayDiff.java   |  6 ++++++
 .../java/codeInspection/DataFlowInspectionTest.java    |  1 +
 3 files changed, 17 insertions(+)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/DoubleArrayDiff.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java
index c0e6a9dc37d6..7da80b23079d 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java
@@ -7,6 +7,7 @@ import com.intellij.codeInsight.Nullability;
 import com.intellij.codeInspection.dataFlow.*;
 import com.intellij.codeInspection.dataFlow.rangeSet.LongRangeSet;
 import com.intellij.codeInspection.dataFlow.types.DfConstantType;
+import com.intellij.codeInspection.dataFlow.types.DfLongType;
 import com.intellij.codeInspection.dataFlow.types.DfType;
 import com.intellij.codeInspection.dataFlow.types.DfTypes;
 import com.intellij.psi.*;
@@ -28,6 +29,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 
+import static com.intellij.codeInspection.dataFlow.types.DfTypes.rangeClamped;
+
 /**
  * @author peter
  */
@@ -235,6 +238,13 @@ public class DfaExpressionFactory {
       return myFactory.fromDfType(SpecialField.ARRAY_LENGTH.asDfType(DfTypes.intValue(length), type));
     }
     DfType dfType = DfTypes.typedObject(type, NullabilityUtil.getExpressionNullability(expression));
+    if (type instanceof PsiPrimitiveType && targetType instanceof PsiPrimitiveType && !type.equals(targetType)) {
+      if (TypeConversionUtil.isIntegralNumberType(targetType)) {
+        LongRangeSet range = DfLongType.extractRange(dfType);
+        return myFactory.fromDfType(rangeClamped(range.castTo((PsiPrimitiveType)targetType), PsiType.LONG.equals(targetType)));
+      }
+      return myFactory.fromDfType(DfTypes.typedObject(targetType, Nullability.UNKNOWN));
+    }
     return DfaUtil.boxUnbox(myFactory.fromDfType(dfType), targetType);
   }
 
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/DoubleArrayDiff.java b/java/java-tests/testData/inspection/dataFlow/fixture/DoubleArrayDiff.java
new file mode 100644
index 000000000000..f1338133f1b1
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/DoubleArrayDiff.java
@@ -0,0 +1,6 @@
+public class DoubleArrayDiff {
+  public static void test(int[] a, int[] b) {
+    double[] d1 = new double[]{b[0] - a[0], b[1] - a[1]};
+    if (d1[1] != 0.0) { }
+  }
+}
\ 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 bf82ebc212a3..aac5c067b5f7 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
@@ -681,4 +681,5 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
   public void testBoxingShortByte() { doTest(); }
   public void testNullableAliasing() { doTest(); }
   public void testReapplyTypeArguments() { doTest(); }
+  public void testDoubleArrayDiff() { doTest(); }
 }