From c4e72cac0bed6a6795cb53867bb77d45a0fb43b5 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <tagir.valeev@jetbrains.com>
Date: Tue, 18 Mar 2025 12:55:55 +0100
Subject: [PATCH] [java-dfa] IDEA-358087 Local variable nullability annotations
 are ignored with default qualifier

GitOrigin-RevId: e640517083910df691b58415f7ba706be37223ec
---
 .../codeInsight/NullableNotNullManager.java   | 32 +++++++++++++++++--
 .../CheckerLocalVariableOverridesDefault.java | 10 ++++++
 .../DataFlowInspection16Test.java             |  5 +++
 3 files changed, 44 insertions(+), 3 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/CheckerLocalVariableOverridesDefault.java

diff --git a/java/java-psi-api/src/com/intellij/codeInsight/NullableNotNullManager.java b/java/java-psi-api/src/com/intellij/codeInsight/NullableNotNullManager.java
index 21fbda713781..7dad00de0e14 100644
--- a/java/java-psi-api/src/com/intellij/codeInsight/NullableNotNullManager.java
+++ b/java/java-psi-api/src/com/intellij/codeInsight/NullableNotNullManager.java
@@ -7,6 +7,7 @@ import com.intellij.openapi.util.Ref;
 import com.intellij.psi.*;
 import com.intellij.psi.util.InheritanceUtil;
 import com.intellij.psi.util.PsiUtil;
+import com.intellij.util.ObjectUtils;
 import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -262,8 +263,13 @@ public abstract class NullableNotNullManager {
       return new NullabilityAnnotationInfo(memberAnno.annotation, nullability, memberAnno.owner == owner ? null : memberAnno.owner, false);
     }
     if (type instanceof PsiPrimitiveType) return null;
-    if (owner instanceof PsiLocalVariable) return null;
-    return findAnnotationInTypeHierarchy(type, annotations);
+    NullabilityAnnotationInfo inHierarchy = findAnnotationInTypeHierarchy(type, annotations);
+    if (inHierarchy != null && 
+        owner instanceof PsiLocalVariable && 
+        !canAnnotateLocals(inHierarchy.getAnnotation().getQualifiedName())) {
+      return null;
+    }
+    return inHierarchy;
   }
 
   protected @NotNull Nullability correctNullability(@NotNull Nullability nullability, @NotNull PsiAnnotation annotation) {
@@ -435,10 +441,18 @@ public abstract class NullableNotNullManager {
         }
       }
       if (!(eachType instanceof PsiClassType)) return true;
+      PsiClassType classType = (PsiClassType)eachType;
       PsiClass targetClass = PsiUtil.resolveClassInClassTypeOnly(eachType);
       if (!(targetClass instanceof PsiTypeParameter)) return false;
       if (targetClass.getExtendsListTypes().length == 0) {
-        NullabilityAnnotationInfo info = findNullabilityDefault(targetClass, PsiAnnotation.TargetType.TYPE_PARAMETER);
+        PsiAnnotation.TargetType[] targetType;
+        PsiModifierListOwner owner = getOwner(classType);
+        if (owner != null) {
+          targetType = AnnotationTargetUtil.getTargetsForLocation(owner.getModifierList());
+        } else {
+          targetType = new PsiAnnotation.TargetType[]{PsiAnnotation.TargetType.TYPE_PARAMETER};
+        }
+        NullabilityAnnotationInfo info = findNullabilityDefault(targetClass, targetType);
         if (info != null) {
           result.set(info);
           return false;
@@ -448,6 +462,18 @@ public abstract class NullableNotNullManager {
     });
     return result.get();
   }
+  
+  private static PsiModifierListOwner getOwner(@NotNull PsiClassType classType) {
+    PsiJavaCodeReferenceElement context = ObjectUtils.tryCast(classType.getPsiContext(), PsiJavaCodeReferenceElement.class);
+    if (context != null) {
+      PsiTypeElement typeElement = ObjectUtils.tryCast(context.getParent(), PsiTypeElement.class);
+      if (typeElement != null) {
+        PsiModifierListOwner owner = ObjectUtils.tryCast(typeElement.getParent(), PsiModifierListOwner.class);
+        return owner;
+      }
+    }
+    return null;
+  }
 
   protected interface NullabilityAnnotationDataHolder {
     /**
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/CheckerLocalVariableOverridesDefault.java b/java/java-tests/testData/inspection/dataFlow/fixture/CheckerLocalVariableOverridesDefault.java
new file mode 100644
index 000000000000..7be50653ea6a
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/CheckerLocalVariableOverridesDefault.java
@@ -0,0 +1,10 @@
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+final class Main {
+  public static void main(final String[] args) {
+    final @Nullable String foo = null;
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection16Test.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection16Test.java
index 4a09f85e3913..38247e85ac1f 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection16Test.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection16Test.java
@@ -47,6 +47,11 @@ public class DataFlowInspection16Test extends DataFlowInspectionTestCase {
     doTest();
   }
   
+  public void testCheckerLocalVariableOverridesDefault() {
+    addCheckerAnnotations(myFixture);
+    doTest();
+  }
+  
   public void testRecordComponentAnnotate() {
     doTest();
     IntentionAction intention = myFixture.findSingleIntention("Annotate record component 'member' as '@Nullable'");