From 6522175598ec3009166a0dfae03ddee7ac8d889d Mon Sep 17 00:00:00 2001
From: Tagir Valeev <tagir.valeev@jetbrains.com>
Date: Tue, 10 May 2022 17:15:39 +0200
Subject: [PATCH] [java-analysis] Check field finality when deciding whether
 class is immutable

Fixes IDEA-293687 Incorrectly claims "expression is always false"

GitOrigin-RevId: 74a3d8f7b3b0a66a974aa35d55147cbc3336393f
---
 .../fixture/FieldUpdateViaSetter.java         | 25 +++++++++++++++++++
 .../DataFlowInspectionTest.java               |  1 +
 .../src/com/siyeh/ig/psiutils/ClassUtils.java |  5 ++--
 3 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/FieldUpdateViaSetter.java

diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/FieldUpdateViaSetter.java b/java/java-tests/testData/inspection/dataFlow/fixture/FieldUpdateViaSetter.java
new file mode 100644
index 000000000000..a91473ea5ee4
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/FieldUpdateViaSetter.java
@@ -0,0 +1,25 @@
+// IDEA-293687
+public class FieldUpdateViaSetter {
+  private static final MutableBoolean flag = new MutableBoolean();
+
+  public static void main(String[] args) {
+    for (int i = 0; i < 10; ++i) {
+      if (flag.value && i == 0) {
+        break;
+      }
+      if (flag.value && i == 3) {
+        System.out.println("IDEA thinks we can't get here");
+        break;
+      }
+      flag.setValue(true);
+    }
+  }
+
+  private static final class MutableBoolean {
+    private boolean value;
+
+    public void setValue(boolean newValue) {
+      value = newValue;
+    }
+  }
+}
\ 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 c0b1fd3b961d..42181265e233 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java
@@ -697,6 +697,7 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
   public void testBoxedDivisionComparison() { doTest(); }
   public void testUnknownComparedToNullable() { doTest(); }
   public void testCastInCatch() { doTest(); }
+  public void testFieldUpdateViaSetter() { doTest(); }
   public void testInitArrayInConstructor() { doTest(); }
   public void testGetterNullityAfterCheck() { doTest(); }
   public void testInferenceNullityMismatch() { doTestWith(insp -> insp.SUGGEST_NULLABLE_ANNOTATIONS = false); }
diff --git a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ClassUtils.java b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ClassUtils.java
index 5f74b7e73cea..a1be6b9c0ec9 100644
--- a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ClassUtils.java
+++ b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ClassUtils.java
@@ -152,8 +152,9 @@ public final class ClassUtils {
     return aClass.hasModifierProperty(PsiModifier.FINAL) &&
            Arrays.stream(aClass.getAllFields())
              .filter(field -> !field.hasModifierProperty(PsiModifier.STATIC))
-             .map(field -> field.getType())
-             .allMatch(type -> TypeConversionUtil.isPrimitiveAndNotNull(type) || immutableTypes.contains(type.getCanonicalText()));
+             .allMatch(field -> field.hasModifierProperty(PsiModifier.FINAL) &&
+                                (TypeConversionUtil.isPrimitiveAndNotNull(field.getType()) ||
+                                 immutableTypes.contains(field.getType().getCanonicalText())));
   }
 
   public static boolean inSamePackage(@Nullable PsiElement element1, @Nullable PsiElement element2) {