From a7a9a7e7166514e57dee6348bd7fe59e68fc4a57 Mon Sep 17 00:00:00 2001
From: Dmitry Batrak <Dmitry.Batrak@jetbrains.com>
Date: Fri, 19 Jan 2018 19:36:39 +0300
Subject: [PATCH] IDEA-185183 Performance degradation in tests on 181 branch

forgotten case
---
 .../folding/impl/PsiNamesElementSignatureProvider.java           | 1 +
 1 file changed, 1 insertion(+)

diff --git a/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java b/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java
index bd63ee6f81c9..32aa1c0fdbc7 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.java
@@ -181,6 +181,7 @@ public class PsiNamesElementSignatureProvider extends AbstractElementSignaturePr
         return null;
       }
       int index = getChildIndex(named, element.getParent(), name, PsiNamedElement.class);
+      if (index < 0) return null;
       StringBuilder bufferToUse = buffer;
       if (bufferToUse == null) {
         bufferToUse = new StringBuilder();