When the substitude command is given an empty pattern, use the previous search pattern instead of firing an error.
When the substitude command is given an empty pattern, use the previous search pattern instead of firing an error.

yixiang/XVim,xuebuhui52011/XVim,weizhenwei/XVim,hmuronaka/XVim,kgoodier/XVim,EmuxEvans/XVim,otfsenter/XVim,liwangwang123/XVim,tanxxjun321/XVim,hyperspacemark/XVim,dengcqw/XVim_x,tanxxjun321/XVim,hyperspacemark/XVim,N4tr0n/XVim,ishkawa/XVim,scottsievert/XVim,pebble8888/XVim,brucehappy/XVim,weizhenwei/XVim,brucehappy/XVim,tkuichooseyou/XVim,EmuxEvans/XVim,XVimProject/XVim,pebble8888/XVim,xuebuhui52011/XVim,teemobean/XVim,EmuxEvans/XVim,thatchristoph/XVim,tkuichooseyou/XVim,Chenkaiang/XVim,raimon49/XVim,teemobean/XVim,gecko655/XVim,tanxxjun321/XVim,hyperspacemark/XVim,yixiang/XVim,tanxxjun321/XVim,lisuxia1992/XVim,liwangwang123/XVim,tonyd256/XVim,antmd/XVim,ishkawa/XVim,raimon49/XVim,gecko655/XVim,Chenkaiang/XVim,sunzeboy/XVim,lisuxia1992/XVim,XVimProject/XVim,hmuronaka/XVim,pebble8888/XVim,Chenkaiang/XVim,raimon49/XVim,liwangwang123/XVim,squarefrog/XVim,otfsenter/XVim,thatchristoph/XVim,SampleLiao/XVim,sunzeboy/XVim,dengcqw/XVim_x,scottsievert/XVim,N4tr0n/XVim,ishkawa/XVim,squarefrog/XVim,tkuichooseyou/XVim,scottsievert/XVim,tonyd256/XVim,lisuxia1992/XVim,raimon49/XVim,brucehappy/XVim,N4tr0n/XVim,tkuichooseyou/XVim,squarefrog/XVim,tonyd256/XVim,kgoodier/XVim,SampleLiao/XVim,SampleLiao/XVim,weizhenwei/XVim,yixiang/XVim,Chenkaiang/XVim,XVimProject/XVim,lisuxia1992/XVim,antmd/XVim,hmuronaka/XVim,hyperspacemark/XVim,thatchristoph/XVim,sunzeboy/XVim,hmuronaka/XVim,xuebuhui52011/XVim,SampleLiao/XVim,dengcqw/XVim_x,otfsenter/XVim,brucehappy/XVim,kgoodier/XVim,antmd/XVim,thatchristoph/XVim,scottsievert/XVim,antmd/XVim,EmuxEvans/XVim,tonyd256/XVim,XVimProject/XVim,yixiang/XVim,pebble8888/XVim,liwangwang123/XVim,otfsenter/XVim,weizhenwei/XVim,gecko655/XVim,squarefrog/XVim,dengcqw/XVim_x,teemobean/XVim,gecko655/XVim,kgoodier/XVim,teemobean/XVim,sunzeboy/XVim,ishkawa/XVim,N4tr0n/XVim,xuebuhui52011/XVim