From f59ab840f175f440174a52eadb8ee7eef89b570b Mon Sep 17 00:00:00 2001
From: Gleb Mazovetskiy <glex.spb@gmail.com>
Date: Thu, 14 Jan 2021 00:19:02 +0000
Subject: [PATCH] include/osg/Callback: nullptr -> NULL

Fixes travis, which explictly requires c++98
---
 include/osg/Callback | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/osg/Callback b/include/osg/Callback
index b7a0cc8cb..d6e969b85 100644
--- a/include/osg/Callback
+++ b/include/osg/Callback
@@ -126,7 +126,7 @@ class OSG_EXPORT Callback : public virtual Object {
         static T* findNestedCallback(osg::Callback* callback)
         {
             if (!callback)
-                return nullptr;
+                return NULL;
 
             if (T* cb = dynamic_cast<T*>(callback))
                 return cb;
@@ -139,7 +139,7 @@ class OSG_EXPORT Callback : public virtual Object {
         static const T* findNestedCallback(const osg::Callback* callback)
         {
             if (!callback)
-                return nullptr;
+                return NULL;
 
             if (const T* cb = dynamic_cast<const T*>(callback))
                 return cb;