From b9e6544c21fc6f5e9cb6d6d690957ae9a39d9918 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <tagir.valeev@jetbrains.com>
Date: Mon, 22 Sep 2025 15:11:03 +0200
Subject: [PATCH] [java-highlighting] IDEA-378301 False compilation error on
 var initialization

GitOrigin-RevId: 09b681b763347bcfcadca137d3e0c57cbe39f33a
---
 .../java/codeserver/highlighting/TypeChecker.java |  3 +++
 .../advLVTI/ComplexInheritanceChain.java          | 15 +++++++++++++++
 .../daemon/LightAdvLVTIHighlightingTest.java      |  6 ++++++
 3 files changed, 24 insertions(+)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advLVTI/ComplexInheritanceChain.java

diff --git a/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/TypeChecker.java b/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/TypeChecker.java
index d526bb6c2fb1..6ef6afd80b29 100644
--- a/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/TypeChecker.java
+++ b/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/TypeChecker.java
@@ -84,6 +84,9 @@ final class TypeChecker {
     PsiExpression initializer = variable.getInitializer();
     // array initializer checked in checkArrayInitializerApplicable
     if (initializer == null || initializer instanceof PsiArrayInitializerExpression) return;
+    PsiTypeElement typeElement = variable.getTypeElement();
+    // initializer cannot be incompatible with the inferred type
+    if (typeElement != null && typeElement.isInferredType()) return;
     PsiType lType = variable.getType();
     PsiType rType = initializer.getType();
     myVisitor.myExpressionChecker.checkAssignability(lType, rType, initializer, initializer);
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advLVTI/ComplexInheritanceChain.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advLVTI/ComplexInheritanceChain.java
new file mode 100644
index 000000000000..c78ebeca995e
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advLVTI/ComplexInheritanceChain.java
@@ -0,0 +1,15 @@
+class MyTest {
+  interface BasicResult {}
+  interface BasicSet<R extends BasicResult> {}
+  interface BasicSession<R extends BasicResult, RS extends BasicSet<R>> {}
+
+  interface Result<R extends BasicResult, S extends BasicSession<R, ?>> {}
+
+  static Result<?, ?> create() {
+    return null;
+  }
+
+  public void test() {
+    var x = create();
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightAdvLVTIHighlightingTest.java b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightAdvLVTIHighlightingTest.java
index f8e974651cdd..442a621963c0 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightAdvLVTIHighlightingTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightAdvLVTIHighlightingTest.java
@@ -6,6 +6,7 @@ import com.intellij.codeInsight.daemon.impl.HighlightInfoType;
 import com.intellij.codeInsight.navigation.actions.GotoDeclarationAction;
 import com.intellij.codeInspection.AnonymousCanBeLambdaInspection;
 import com.intellij.codeInspection.redundantCast.RedundantCastInspection;
+import com.intellij.idea.TestFor;
 import com.intellij.openapi.projectRoots.JavaSdkVersion;
 import com.intellij.openapi.projectRoots.Sdk;
 import com.intellij.pom.java.LanguageLevel;
@@ -93,6 +94,11 @@ public class LightAdvLVTIHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testIntersectionTypeMethodRef() {
     doTest();
   }
+  
+  @TestFor(issues = "IDEA-378301")
+  public void testComplexInheritanceChain() {
+    doTest();
+  }
 
   public void testTypeObject() {
     doTest();