fix file completion bug spotted by @wch
fix file completion bug spotted by @wch

jar1karp/rstudio,githubfun/rstudio,maligulzar/Rstudio-instrumented,brsimioni/rstudio,edrogers/rstudio,maligulzar/Rstudio-instrumented,sfloresm/rstudio,john-r-mcpherson/rstudio,piersharding/rstudio,john-r-mcpherson/rstudio,jzhu8803/rstudio,more1/rstudio,jar1karp/rstudio,vbelakov/rstudio,john-r-mcpherson/rstudio,piersharding/rstudio,tbarrongh/rstudio,JanMarvin/rstudio,thklaus/rstudio,more1/rstudio,suribes/rstudio,edrogers/rstudio,pssguy/rstudio,more1/rstudio,pssguy/rstudio,suribes/rstudio,jar1karp/rstudio,vbelakov/rstudio,pssguy/rstudio,sfloresm/rstudio,more1/rstudio,githubfun/rstudio,jar1karp/rstudio,jar1karp/rstudio,vbelakov/rstudio,john-r-mcpherson/rstudio,jrnold/rstudio,tbarrongh/rstudio,thklaus/rstudio,maligulzar/Rstudio-instrumented,piersharding/rstudio,brsimioni/rstudio,githubfun/rstudio,edrogers/rstudio,brsimioni/rstudio,piersharding/rstudio,JanMarvin/rstudio,jrnold/rstudio,vbelakov/rstudio,thklaus/rstudio,piersharding/rstudio,JanMarvin/rstudio,jrnold/rstudio,JanMarvin/rstudio,piersharding/rstudio,jar1karp/rstudio,sfloresm/rstudio,thklaus/rstudio,suribes/rstudio,JanMarvin/rstudio,githubfun/rstudio,brsimioni/rstudio,vbelakov/rstudio,jar1karp/rstudio,vbelakov/rstudio,edrogers/rstudio,sfloresm/rstudio,maligulzar/Rstudio-instrumented,jrnold/rstudio,tbarrongh/rstudio,jzhu8803/rstudio,john-r-mcpherson/rstudio,jrnold/rstudio,pssguy/rstudio,brsimioni/rstudio,sfloresm/rstudio,jrnold/rstudio,thklaus/rstudio,maligulzar/Rstudio-instrumented,githubfun/rstudio,more1/rstudio,jzhu8803/rstudio,vbelakov/rstudio,suribes/rstudio,JanMarvin/rstudio,tbarrongh/rstudio,piersharding/rstudio,thklaus/rstudio,sfloresm/rstudio,githubfun/rstudio,tbarrongh/rstudio,more1/rstudio,jzhu8803/rstudio,piersharding/rstudio,githubfun/rstudio,sfloresm/rstudio,jar1karp/rstudio,pssguy/rstudio,jzhu8803/rstudio,pssguy/rstudio,john-r-mcpherson/rstudio,edrogers/rstudio,jzhu8803/rstudio,jrnold/rstudio,brsimioni/rstudio,brsimioni/rstudio,thklaus/rstudio,tbarrongh/rstudio,tbarrongh/rstudio,githubfun/rstudio,sfloresm/rstudio,jrnold/rstudio,john-r-mcpherson/rstudio,JanMarvin/rstudio,JanMarvin/rstudio,pssguy/rstudio,maligulzar/Rstudio-instrumented,brsimioni/rstudio,tbarrongh/rstudio,maligulzar/Rstudio-instrumented,more1/rstudio,thklaus/rstudio,suribes/rstudio,maligulzar/Rstudio-instrumented,jzhu8803/rstudio,edrogers/rstudio,maligulzar/Rstudio-instrumented,jzhu8803/rstudio,vbelakov/rstudio,john-r-mcpherson/rstudio,piersharding/rstudio,jar1karp/rstudio,suribes/rstudio,pssguy/rstudio,more1/rstudio,suribes/rstudio,edrogers/rstudio,jrnold/rstudio,JanMarvin/rstudio,suribes/rstudio,edrogers/rstudio