fix nullptr issue
fix nullptr issue

yonglehou/vowpal_wabbit,yonglehou/vowpal_wabbit,abimannans/vowpal_wabbit,zachmayer/vowpal_wabbit,obrianjunior/vowpal_wabbit,hhexiy/vowpal_wabbit,printedheart/vowpal_wabbit,stathwang/vowpal_wabbit,raosudha89/vowpal_wabbit,zzzbit/vowpal_wabbit,martinpopel/vowpal_wabbit,emjotde/vowpal_wabbit,trufanov-nok/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,digitalreasoning/vowpal_wabbit,abimannans/vowpal_wabbit,feynman0825/vowpal_wabbit,sandyice74/vowpal_wabbit,zhoususheng/vowpal_wabbit,VerveWireless/vowpal_wabbit,swjo207/vowpal_wabbit,ml-lab/vowpal_wabbit,byzhang/vowpal_wabbit,followyourheart/vowpal_wabbit,zzzbit/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,robin-lai/vowpal_wabbit,byzhang/vowpal_wabbit,hal3/vowpal_wabbit,haipengl/vowpal_wabbit,pombredanne/vowpal_wabbit,stathwang/vowpal_wabbit,followyourheart/vowpal_wabbit,zachmayer/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,martinbel/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,swjo207/vowpal_wabbit,deaktator/vowpal_wabbit,VerveWireless/vowpal_wabbit,ffyu/vowpal_wabbit,ffyu/vowpal_wabbit,martinpopel/vowpal_wabbit,zzzbit/vowpal_wabbit,byzhang/vowpal_wabbit,michaelbrundage/vowpal_wabbit,zhoususheng/vowpal_wabbit,zhoususheng/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,lmatthieu/myvw,raosudha89/vowpal_wabbit,pombredanne/vowpal_wabbit,ml-lab/vowpal_wabbit,lmatthieu/myvw,jmorra/vowpal_wabbit,ml-lab/vowpal_wabbit,VerveWireless/vowpal_wabbit,printedheart/vowpal_wabbit,chenmoshushi/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,raosudha89/vowpal_wabbit,zachmayer/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,followyourheart/vowpal_wabbit,martinpopel/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,ffyu/vowpal_wabbit,printedheart/vowpal_wabbit,emjotde/vowpal_wabbit,zachmayer/vowpal_wabbit,pombredanne/vowpal_wabbit,yonglehou/vowpal_wabbit,hhexiy/vowpal_wabbit,marko-asplund/vowpal_wabbit,digitalreasoning/vowpal_wabbit,digitalreasoning/vowpal_wabbit,robin-lai/vowpal_wabbit,deaktator/vowpal_wabbit,chenmoshushi/vowpal_wabbit,robin-lai/vowpal_wabbit,feynman0825/vowpal_wabbit,hal3/vowpal_wabbit,followyourheart/vowpal_wabbit,feynman0825/vowpal_wabbit,zhoususheng/vowpal_wabbit,yonglehou/vowpal_wabbit,VerveWireless/vowpal_wabbit,lmatthieu/myvw,tzukuoh/vowpal_wabbit,danmelamed/vowpal_wabbit,tzukuoh/vowpal_wabbit,martinbel/vowpal_wabbit,raosudha89/vowpal_wabbit,martinpopel/vowpal_wabbit,deaktator/vowpal_wabbit,tzukuoh/vowpal_wabbit,lhoang29/vowpal_wabbit,hhexiy/vowpal_wabbit,danmelamed/vowpal_wabbit,feynman0825/vowpal_wabbit,ml-lab/vowpal_wabbit,zzzbit/vowpal_wabbit,pombredanne/vowpal_wabbit,zachmayer/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,jmorra/vowpal_wabbit,VerveWireless/vowpal_wabbit,robin-lai/vowpal_wabbit,sandyice74/vowpal_wabbit,emjotde/vowpal_wabbit,martinpopel/vowpal_wabbit,VerveWireless/vowpal_wabbit,raosudha89/vowpal_wabbit,stathwang/vowpal_wabbit,martinbel/vowpal_wabbit,hhexiy/vowpal_wabbit,marko-asplund/vowpal_wabbit,sandyice74/vowpal_wabbit,followyourheart/vowpal_wabbit,deaktator/vowpal_wabbit,obrianjunior/vowpal_wabbit,obrianjunior/vowpal_wabbit,lhoang29/vowpal_wabbit,martinpopel/vowpal_wabbit,ffyu/vowpal_wabbit,swjo207/vowpal_wabbit,haipengl/vowpal_wabbit,emjotde/vowpal_wabbit,haipengl/vowpal_wabbit,followyourheart/vowpal_wabbit,marcovzla/vowpal_wabbit,zzzbit/vowpal_wabbit,haipengl/vowpal_wabbit,stathwang/vowpal_wabbit,hhexiy/vowpal_wabbit,trufanov-nok/vowpal_wabbit,jmorra/vowpal_wabbit,emjotde/vowpal_wabbit,haipengl/vowpal_wabbit,martinpopel/vowpal_wabbit,michaelbrundage/vowpal_wabbit,danmelamed/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,robin-lai/vowpal_wabbit,marko-asplund/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,obrianjunior/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,haipengl/vowpal_wabbit,martinbel/vowpal_wabbit,abimannans/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,zhoususheng/vowpal_wabbit,marko-asplund/vowpal_wabbit,danmelamed/vowpal_wabbit,hhexiy/vowpal_wabbit,lmatthieu/myvw,gregsharp/vowpal_wabbit,hal3/vowpal_wabbit,zhoususheng/vowpal_wabbit,deaktator/vowpal_wabbit,marcovzla/vowpal_wabbit,robin-lai/vowpal_wabbit,jmorra/vowpal_wabbit,sandyice74/vowpal_wabbit,trufanov-nok/vowpal_wabbit,ml-lab/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,abimannans/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,robin-lai/vowpal_wabbit,followyourheart/vowpal_wabbit,VerveWireless/vowpal_wabbit,byzhang/vowpal_wabbit,haipengl/vowpal_wabbit,michaelbrundage/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,hhexiy/vowpal_wabbit,yonglehou/vowpal_wabbit,lhoang29/vowpal_wabbit,tzukuoh/vowpal_wabbit,jmorra/vowpal_wabbit,marcovzla/vowpal_wabbit,zzzbit/vowpal_wabbit,feynman0825/vowpal_wabbit,jmorra/vowpal_wabbit,byzhang/vowpal_wabbit,digitalreasoning/vowpal_wabbit,stathwang/vowpal_wabbit,chenmoshushi/vowpal_wabbit,zachmayer/vowpal_wabbit,emjotde/vowpal_wabbit,raosudha89/vowpal_wabbit,digitalreasoning/vowpal_wabbit,hal3/vowpal_wabbit,ml-lab/vowpal_wabbit,tzukuoh/vowpal_wabbit,zachmayer/vowpal_wabbit,lhoang29/vowpal_wabbit,pombredanne/vowpal_wabbit,digitalreasoning/vowpal_wabbit,lhoang29/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,abimannans/vowpal_wabbit,deaktator/vowpal_wabbit,sandyice74/vowpal_wabbit,gregsharp/vowpal_wabbit,digitalreasoning/vowpal_wabbit,haipengl/vowpal_wabbit,tzukuoh/vowpal_wabbit,printedheart/vowpal_wabbit,gregsharp/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,danmelamed/vowpal_wabbit,abimannans/vowpal_wabbit,printedheart/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,danmelamed/vowpal_wabbit,abimannans/vowpal_wabbit,pombredanne/vowpal_wabbit,marcovzla/vowpal_wabbit,gregsharp/vowpal_wabbit,raosudha89/vowpal_wabbit,stathwang/vowpal_wabbit,feynman0825/vowpal_wabbit,followyourheart/vowpal_wabbit,haipengl/vowpal_wabbit,stathwang/vowpal_wabbit,yonglehou/vowpal_wabbit,ml-lab/vowpal_wabbit,followyourheart/vowpal_wabbit,zzzbit/vowpal_wabbit,stathwang/vowpal_wabbit,yonglehou/vowpal_wabbit,yonglehou/vowpal_wabbit,swjo207/vowpal_wabbit,hal3/vowpal_wabbit,marko-asplund/vowpal_wabbit,michaelbrundage/vowpal_wabbit,swjo207/vowpal_wabbit,hal3/vowpal_wabbit,martinpopel/vowpal_wabbit,jmorra/vowpal_wabbit,danmelamed/vowpal_wabbit,robin-lai/vowpal_wabbit,martinbel/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,trufanov-nok/vowpal_wabbit,printedheart/vowpal_wabbit,lhoang29/vowpal_wabbit,digitalreasoning/vowpal_wabbit,byzhang/vowpal_wabbit,yonglehou/vowpal_wabbit,stathwang/vowpal_wabbit,zzzbit/vowpal_wabbit,deaktator/vowpal_wabbit,printedheart/vowpal_wabbit,obrianjunior/vowpal_wabbit,gregsharp/vowpal_wabbit,raosudha89/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,swjo207/vowpal_wabbit,lmatthieu/myvw,obrianjunior/vowpal_wabbit,lmatthieu/myvw,martinbel/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,feynman0825/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,ffyu/vowpal_wabbit,byzhang/vowpal_wabbit,swjo207/vowpal_wabbit,jmorra/vowpal_wabbit,hal3/vowpal_wabbit,ml-lab/vowpal_wabbit,marko-asplund/vowpal_wabbit,tzukuoh/vowpal_wabbit,yonglehou/vowpal_wabbit,byzhang/vowpal_wabbit,hal3/vowpal_wabbit,pombredanne/vowpal_wabbit,obrianjunior/vowpal_wabbit,marcovzla/vowpal_wabbit,swjo207/vowpal_wabbit,hhexiy/vowpal_wabbit,ffyu/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,chenmoshushi/vowpal_wabbit,michaelbrundage/vowpal_wabbit,trufanov-nok/vowpal_wabbit,sandyice74/vowpal_wabbit,ffyu/vowpal_wabbit,jmorra/vowpal_wabbit,gregsharp/vowpal_wabbit,haipengl/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,digitalreasoning/vowpal_wabbit,obrianjunior/vowpal_wabbit,danmelamed/vowpal_wabbit,emjotde/vowpal_wabbit,printedheart/vowpal_wabbit,michaelbrundage/vowpal_wabbit,marcovzla/vowpal_wabbit,danmelamed/vowpal_wabbit,emjotde/vowpal_wabbit,abimannans/vowpal_wabbit,zhoususheng/vowpal_wabbit,pombredanne/vowpal_wabbit,gregsharp/vowpal_wabbit,sandyice74/vowpal_wabbit,tzukuoh/vowpal_wabbit,zachmayer/vowpal_wabbit,lhoang29/vowpal_wabbit,byzhang/vowpal_wabbit,deaktator/vowpal_wabbit,stathwang/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,zhoususheng/vowpal_wabbit,obrianjunior/vowpal_wabbit,sandyice74/vowpal_wabbit,tzukuoh/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,chenmoshushi/vowpal_wabbit,chenmoshushi/vowpal_wabbit,ml-lab/vowpal_wabbit,feynman0825/vowpal_wabbit,martinpopel/vowpal_wabbit,trufanov-nok/vowpal_wabbit,ml-lab/vowpal_wabbit,feynman0825/vowpal_wabbit,tzukuoh/vowpal_wabbit,lhoang29/vowpal_wabbit,martinbel/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,elkingtonmcb/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,deaktator/vowpal_wabbit,printedheart/vowpal_wabbit,pombredanne/vowpal_wabbit,ffyu/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,emjotde/vowpal_wabbit,trufanov-nok/vowpal_wabbit,byzhang/vowpal_wabbit,zachmayer/vowpal_wabbit,martinbel/vowpal_wabbit,zhoususheng/vowpal_wabbit,michaelbrundage/vowpal_wabbit,abimannans/vowpal_wabbit,marcovzla/vowpal_wabbit,danmelamed/vowpal_wabbit,trufanov-nok/vowpal_wabbit,trufanov-nok/vowpal_wabbit,gregsharp/vowpal_wabbit,hal3/vowpal_wabbit,raosudha89/vowpal_wabbit,ffyu/vowpal_wabbit,gregsharp/vowpal_wabbit,chenmoshushi/vowpal_wabbit,chenmoshushi/vowpal_wabbit,marcovzla/vowpal_wabbit,followyourheart/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,michaelbrundage/vowpal_wabbit,pombredanne/vowpal_wabbit,lhoang29/vowpal_wabbit,martinbel/vowpal_wabbit,marcovzla/vowpal_wabbit,gregsharp/vowpal_wabbit,lmatthieu/myvw,sandyice74/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,swjo207/vowpal_wabbit,marko-asplund/vowpal_wabbit,digitalreasoning/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,robin-lai/vowpal_wabbit,deaktator/vowpal_wabbit-jmorra,elkingtonmcb/vowpal_wabbit,marko-asplund/vowpal_wabbit,swjo207/vowpal_wabbit,hal3/vowpal_wabbit,martinbel/vowpal_wabbit,abimannans/vowpal_wabbit,jon-morra-zefr/vowpal_wabbit,michaelbrundage/vowpal_wabbit,hhexiy/vowpal_wabbit,zzzbit/vowpal_wabbit,marko-asplund/vowpal_wabbit,trufanov-nok/vowpal_wabbit,zzzbit/vowpal_wabbit,michaelbrundage/vowpal_wabbit,lhoang29/vowpal_wabbit,robin-lai/vowpal_wabbit,zachmayer/vowpal_wabbit,raosudha89/vowpal_wabbit,printedheart/vowpal_wabbit,hal3/vowpal_wabbit,feynman0825/vowpal_wabbit,marko-asplund/vowpal_wabbit,chenmoshushi/vowpal_wabbit,zhoususheng/vowpal_wabbit,obrianjunior/vowpal_wabbit,chenmoshushi/vowpal_wabbit,VerveWireless/vowpal_wabbit,ffyu/vowpal_wabbit,VerveWireless/vowpal_wabbit,lmatthieu/myvw,lmatthieu/myvw,deaktator/vowpal_wabbit,marcovzla/vowpal_wabbit,KaiWeiChang/vowpal_wabbit,sandyice74/vowpal_wabbit,deaktator/vowpal_wabbit,emjotde/vowpal_wabbit,jmorra/vowpal_wabbit,VerveWireless/vowpal_wabbit,martinpopel/vowpal_wabbit,hhexiy/vowpal_wabbit