From 451bc27edb1502edf1482d4ffeee651cddbb7257 Mon Sep 17 00:00:00 2001
From: Sergey Linev <S.Linev@gsi.de>
Date: Thu, 27 Oct 2016 10:52:50 +0200
Subject: [PATCH] json: write null when const char* = 0

Signed-off-by: Sergey Linev <S.Linev@gsi.de>
---
 io/io/src/TBufferJSON.cxx | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/io/io/src/TBufferJSON.cxx b/io/io/src/TBufferJSON.cxx
index 81753f8554c71..ac41236cc931d 100644
--- a/io/io/src/TBufferJSON.cxx
+++ b/io/io/src/TBufferJSON.cxx
@@ -3047,9 +3047,14 @@ void TBufferJSON::JsonWriteBasic(ULong64_t value)
 
 void TBufferJSON::JsonWriteConstChar(const char* value, Int_t len)
 {
-   fValue.Append("\"");
+   if (value==0) {
+
+      fValue.Append("null");
+
+   } else {
+
+      fValue.Append("\"");
 
-   if (value!=0) {
       if (len<0) len = strlen(value);
 
       for (Int_t n=0;n<len;n++) {
@@ -3086,9 +3091,9 @@ void TBufferJSON::JsonWriteConstChar(const char* value, Int_t len)
                   fValue.Append(TString::Format("\\u%04x", (unsigned) c));
          }
       }
-   }
 
-   fValue.Append("\"");
+      fValue.Append("\"");
+   }
 }