[java] tolerate recursive applicability check

EA-239076 - NPE: MethodCandidateInfo.inferTypeArguments; possible if `var` type variable contains self reference in its initializer

GitOrigin-RevId: b0fb15c563d41b5124a381988e335162c723cd5e

java/java-psi-api/src/com/intellij/psi/infos/MethodCandidateInfo.java

@@ -164,8 +164,11 @@ public class MethodCandidateInfo extends CandidateInfo{
       }
       return level1;
     }, substitutor);
-    @ApplicabilityLevelConstant int level =
-      Objects.requireNonNull(ourOverloadGuard.doPreventingRecursion(myArgumentList, false, computable));
+    Integer applicabilityLevel = ourOverloadGuard.doPreventingRecursion(myArgumentList, false, computable);
+    if (applicabilityLevel == null) {
+      return ApplicabilityLevel.NOT_APPLICABLE;
+    }
+    @ApplicabilityLevelConstant int level = applicabilityLevel;
     if (level > ApplicabilityLevel.NOT_APPLICABLE && !isTypeArgumentsApplicable(() -> substitutor)) {
       level = ApplicabilityLevel.NOT_APPLICABLE;
     }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advLVTI/RecursiveInference.java

@@ -0,0 +1,12 @@
+import java.util.function.Function;
+
+class MyTest {
+ 
+  <T> java.util.List<T> f(Function<T, String> ff) {
+    return null;
+  }
+
+  void test() {
+    var t = this.<String><caret>f(t);
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightAdvLVTIHighlightingTest.java

@@ -12,6 +12,8 @@ import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.CommonClassNames;
 import com.intellij.psi.PsiClass;
 import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiMethodCallExpression;
+import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.testFramework.IdeaTestUtil;
 
 public class LightAdvLVTIHighlightingTest extends LightDaemonAnalyzerTestCase {
@@ -56,6 +58,13 @@ public class LightAdvLVTIHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testFailedInferenceWithLeftTypeVar() { doTest(); }
   public void testDisjunctionType() { doTest(); }
 
+  public void testRecursiveInference() {
+    configureByFile(BASE_PATH + "/" + getTestName(false) + ".java");
+    final int offset = getEditor().getCaretModel().getOffset();
+    PsiMethodCallExpression expression = PsiTreeUtil.getParentOfType(getFile().findElementAt(offset), PsiMethodCallExpression.class);
+    assertTrue(expression.resolveMethodGenerics().isValidResult());
+  }
+
   public void testVarInLambdaParameters() {
     setLanguageLevel(LanguageLevel.JDK_11);
     doTest();