From ff1cfed0de5c93a4c8c43836a23853ede270199d Mon Sep 17 00:00:00 2001
From: Tagir Valeev <tagir.valeev@jetbrains.com>
Date: Wed, 17 Apr 2024 11:53:26 +0200
Subject: [PATCH] [java-dfa] Do not assume that fields are non-initialized in
 readResolve() when readObject() is present

Fixes IDEA-351947 False positive warning 'Nullability and data flow problems' in readResolve

GitOrigin-RevId: 26c71c3e26c087334741a5a098812f91144bdcd4
---
 .../jvm/descriptors/PlainDescriptor.java      | 12 +++++--
 .../dataFlow/fixture/ReadResolve2.java        | 31 +++++++++++++++++++
 .../DataFlowInspection21Test.java             |  1 +
 3 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/ReadResolve2.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/jvm/descriptors/PlainDescriptor.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/jvm/descriptors/PlainDescriptor.java
index 22e982720eb0..c51b0ab73b8f 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/jvm/descriptors/PlainDescriptor.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/jvm/descriptors/PlainDescriptor.java
@@ -18,6 +18,8 @@ import com.intellij.psi.*;
 import com.intellij.psi.util.*;
 import com.intellij.util.JavaPsiConstructorUtil;
 import com.intellij.util.ObjectUtils;
+import com.intellij.util.containers.ContainerUtil;
+import com.siyeh.ig.callMatcher.CallMatcher;
 import com.siyeh.ig.psiutils.ExpressionUtils;
 import com.siyeh.ig.psiutils.VariableAccessUtils;
 import org.jetbrains.annotations.NotNull;
@@ -159,16 +161,20 @@ public final class PlainDescriptor extends PsiVarDescriptor {
     if (!placeMethod.hasModifierProperty(PsiModifier.STATIC) && target.hasModifierProperty(PsiModifier.STATIC)) return false;
     if (!target.hasModifierProperty(PsiModifier.STATIC) &&
         !placeMethod.hasModifierProperty(PsiModifier.STATIC) &&
-        (isReadResolveMethod(placeMethod, placeClass) ||
+        (isReadResolveMethodWithoutReadObject(placeMethod, placeClass) ||
          methodCanBeCalledFromConstructorBeforeFieldInitializing(target, placeMethod, placeClass))) {
       return true;
     }
     return getAccessOffset(placeMethod) < getWriteOffset(target);
   }
 
-  private static boolean isReadResolveMethod(@NotNull PsiMethod method, @NotNull PsiClass aClass) {
+  private static final CallMatcher READ_OBJECT = CallMatcher.instanceCall(CommonClassNames.JAVA_LANG_OBJECT, "readObject")
+    .parameterTypes("java.io.ObjectInputStream");  
+
+  private static boolean isReadResolveMethodWithoutReadObject(@NotNull PsiMethod method, @NotNull PsiClass aClass) {
     return "readResolve".equals(method.getName()) && method.getParameterList().isEmpty() &&
-           InheritanceUtil.isInheritor(aClass, CommonClassNames.JAVA_IO_SERIALIZABLE);
+           !aClass.isRecord() && InheritanceUtil.isInheritor(aClass, CommonClassNames.JAVA_IO_SERIALIZABLE) &&
+           !ContainerUtil.exists(aClass.findMethodsByName("readObject", false), READ_OBJECT::methodMatches);
    }
 
   private record TargetCallInfo(@NotNull PsiMethod constructor,
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/ReadResolve2.java b/java/java-tests/testData/inspection/dataFlow/fixture/ReadResolve2.java
new file mode 100644
index 000000000000..132a9e5a0bcb
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/ReadResolve2.java
@@ -0,0 +1,31 @@
+import org.jetbrains.annotations.NotNull;
+
+import java.io.*;
+import java.util.Base64;
+
+class Test implements Serializable {
+  @NotNull String string;
+
+  Test(@NotNull String string) {
+    this.string = string;
+  }
+
+  @Serial
+  private void readObject(ObjectInputStream in) throws IOException {
+    this.string = in.readUTF();
+  }
+
+  @Serial
+  protected Object readResolve() {
+    if (<warning descr="Condition 'string == null' is always 'false'">string == null</warning>) {
+      throw new IllegalStateException("Wrong object!");
+    }
+    return this;
+  }
+
+  public static void main(String[] args) throws IOException, ClassNotFoundException {
+    byte[] data = Base64.getDecoder().decode("rO0ABXNyAARUZXN0ST9d8XKvH/0CAAFMAAZzdHJpbmd0ABJMamF2YS9sYW5nL1N0cmluZzt4cHA=");
+    Test object = (Test) new ObjectInputStream(new ByteArrayInputStream(data)).readObject();
+    System.out.println(object);
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java
index 1d29ed6d532e..a5eace25c853 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection21Test.java
@@ -114,6 +114,7 @@ public class DataFlowInspection21Test extends DataFlowInspectionTestCase {
     doTest();
   }
   public void testReadResolve() { doTest(); }
+  public void testReadResolve2() { doTest(); }
   public void testDifferentTypesButNullable() { doTest(); }
 
   public void testForEachPattern() {