new overload resolution

java/java-psi-api/src/com/intellij/psi/PsiMethodReferenceUtil.java

@@ -18,6 +18,7 @@ package com.intellij.psi;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.project.Project;
 import com.intellij.pom.java.LanguageLevel;
+import com.intellij.psi.infos.MethodCandidateInfo;
 import com.intellij.psi.util.*;
 import com.intellij.util.Function;
 import com.sun.tools.javac.code.Kinds;
@@ -163,6 +164,10 @@ public class PsiMethodReferenceUtil {
 
   public static boolean isAcceptable(@Nullable final PsiMethodReferenceExpression methodReferenceExpression, PsiType left) {
     if (methodReferenceExpression == null) return false;
+    final PsiElement argsList = PsiTreeUtil.getParentOfType(methodReferenceExpression, PsiExpressionList.class);
+    if (MethodCandidateInfo.ourOverloadGuard.currentStack().contains(argsList)) {
+      if (!methodReferenceExpression.isExact()) return true;
+    }
     if (left instanceof PsiIntersectionType) {
       for (PsiType conjunct : ((PsiIntersectionType)left).getConjuncts()) {
         if (isAcceptable(methodReferenceExpression, conjunct)) return true;

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

@@ -18,8 +18,10 @@ package com.intellij.psi.infos;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.projectRoots.JavaSdkVersion;
 import com.intellij.openapi.projectRoots.JavaVersionService;
+import com.intellij.openapi.util.Computable;
 import com.intellij.openapi.util.Pair;
 import com.intellij.openapi.util.RecursionGuard;
+import com.intellij.openapi.util.RecursionManager;
 import com.intellij.openapi.util.registry.Registry;
 import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
@@ -37,6 +39,7 @@ import java.util.Map;
  * @author ik, dsl
  */
 public class MethodCandidateInfo extends CandidateInfo{
+  public static final RecursionGuard ourOverloadGuard = RecursionManager.createGuard("overload.guard");
   public static final ThreadLocal<Map<PsiElement,  Pair<PsiMethod, PsiSubstitutor>>> CURRENT_CANDIDATE = new ThreadLocal<Map<PsiElement,  Pair<PsiMethod, PsiSubstitutor>>>();
   @ApplicabilityLevelConstant private int myApplicabilityLevel = 0;
   private final PsiElement myArgumentList;
@@ -95,6 +98,20 @@ public class MethodCandidateInfo extends CandidateInfo{
     return myApplicabilityLevel;
   }
 
+  @ApplicabilityLevelConstant
+  public int getPertinentApplicabilityLevel() {
+    final PsiMethod method = getElement();
+    if (method != null && method.hasTypeParameters() || myArgumentList == null || !PsiUtil.isLanguageLevel8OrHigher(myArgumentList)) {
+      return getApplicabilityLevel();
+    }
+    return ourOverloadGuard.doPreventingRecursion(myArgumentList, false, new Computable<Integer>() {
+      @Override
+      public Integer compute() {
+        return getApplicabilityLevelInner();
+      }
+    });
+  }
+
   public PsiSubstitutor getSiteSubstitutor() {
     return super.getSubstitutor();
   }

java/java-psi-impl/src/com/intellij/psi/scope/conflictResolvers/JavaMethodsConflictResolver.java

@@ -394,7 +394,7 @@ public class JavaMethodsConflictResolver implements PsiConflictResolver{
       for (Iterator<CandidateInfo> iterator = conflicts.iterator(); iterator.hasNext();) {
         ProgressManager.checkCanceled();
         CandidateInfo info = iterator.next();
-        final int level = preferVarargs(info);
+        final int level = preferVarargs((MethodCandidateInfo)info);
         if (level < maxApplicabilityLevel) {
           iterator.remove();
         }
@@ -404,10 +404,10 @@ public class JavaMethodsConflictResolver implements PsiConflictResolver{
     return maxApplicabilityLevel;
   }
 
-  private static int preferVarargs(CandidateInfo info) {
-    final int level = ((MethodCandidateInfo)info).getApplicabilityLevel();
+  private static int preferVarargs(MethodCandidateInfo info) {
+    final int level = info.getPertinentApplicabilityLevel();
     if (level == MethodCandidateInfo.ApplicabilityLevel.FIXED_ARITY) {
-      final PsiMethod psiMethod = (PsiMethod)info.getElement();
+      final PsiMethod psiMethod = info.getElement();
       if (psiMethod != null && psiMethod.isVarArgs() && JavaVersionService.getInstance().isAtLeast(psiMethod, JavaSdkVersion.JDK_1_7)) {
         return level + 1;
       }