check on swapped pair

diff --git a/HBTAN/AliHBTFunction.h b/HBTAN/AliHBTFunction.h
index 5d86a9ee068404af4b555ec1eed0910583557f1d..48c449c4196c720ab01b51db3170998240f3a31b 100644 (file)
--- a/HBTAN/AliHBTFunction.h
+++ b/HBTAN/AliHBTFunction.h
@@ -49,10 +49,11 @@ inline AliHBTPair* AliHBTFunction::CheckPair(AliHBTPair* pair)
   if(fPairCut->Pass(pair)) //if the pair is BAD
    {//it is BAD 
     pair = pair->GetSwapedPair();
-    if(fPairCut->Pass(pair)) //so try reverse combination
-     { 
-       return 0x0;//it is BAD as well - so return
-     }
+    if(pair)
+     if(fPairCut->Pass(pair)) //so try reverse combination
+       { 
+        return 0x0;//it is BAD as well - so return
+       }
    }
   return pair; 
 }