[xml mode] Fix bug with value-less attributes
[xml mode] Fix bug with value-less attributes

Closes #2112

wingify/CodeMirror,kangkot/CodeMirror,TechnicalPursuit/CodeMirror,hackmdio/CodeMirror,SidPresse/CodeMirror,camellhf/CodeMirror,wingify/CodeMirror,amshali/CodeMirror,mizchi/CodeMirror,kangkot/CodeMirror,mightyguava/CodeMirror,ssxxue/CodeMirror,schanzer/CodeMirror,matthewbauer/CodeMirror,kevinushey/CodeMirror,dudb/CodeMirror,supriyantomaftuh/CodeMirror,karevn/CodeMirror,matthewbauer/CodeMirror,dudb/CodeMirror,jayaprabhakar/CodeMirror,mizchi/CodeMirror,elisee/CodeMirror,rrandom/CodeMirror,symbla/CodeMirror,djadmin/CodeMirror,codio/CodeMirror,SidPresse/CodeMirror,ficristo/CodeMirror,alur/CodeMirror,codio/CodeMirror,wbinnssmith/CodeMirror,symbla/CodeMirror,amshali/CodeMirror,thomasjm/CodeMirror,nawroth/CodeMirror,mtaran-google/CodeMirror,manderson23/CodeMirror,xeronith/CodeMirror,melpon/CodeMirror,sanyaade-iot/CodeMirror,bocharsky-bw/CodeMirror,dperetti/CodeMirror,DustinH/CodeMirror,dperetti/CodeMirror,elisee/CodeMirror,kk9599/CodeMirror,jessegrosjean/CodeMirror,sourcelair/CodeMirror,fmoliveira/CodeMirror,Navaneethsen/CodeMirror,morrisonwudi/CodeMirror,nightwing/CodeMirror,fmoliveira/CodeMirror,CartoDB/CodeMirror,tpphu/CodeMirror,crazy4chrissi/CodeMirror,apatawari/CodeMirror,ZombieHippie/CodeMirror,Dominator008/CodeMirror,d0liver/CodeMirror,philuchansky/CodeMirror,Icenium/CodeMirror,axter/CodeMirror,ThebingServices/CodeMirror,AlanWasTaken/codemirror,InternetGuru/CodeMirror,Aliccer/CodeMirror,TDaglis/CodeMirror,Aliccer/CodeMirror,qweasd1/CodeMirror,grzegorzmazur/CodeMirror,vincentwoo/CodeMirror,ZombieHippie/CodeMirror,buchslava/CodeMirror,rrandom/CodeMirror,manderson23/CodeMirror,Icenium/CodeMirror,camellhf/CodeMirror,NeZaMy/CodeMirror2,rasata/CodeMirror,abdelouahabb/CodeMirror,buchslava/CodeMirror,buchslava/CodeMirror,mihailik/CodeMirror,TDaglis/CodeMirror,djadmin/CodeMirror,jessegrosjean/CodeMirror,agendor/CodeMirror,bfrohs/CodeMirror,joshterrell805-historic/CodeMirror,karthikeyansam/CodeMirror,notepadqq/CodeMirror,shiren/CodeMirror,TDaglis/CodeMirror,adobe/CodeMirror2,increpare/CodeMirror,MarcelGerber/CodeMirror,wbinnssmith/CodeMirror,belph/CodeMirror,hccampos/CodeMirror,ksanaforge/CodeMirror,GerHobbelt/CodeMirror2,cben/CodeMirror,pinbe/CodeMirror,increpare/CodeMirror,mtaran-google/CodeMirror,mizchi/CodeMirror,bgrins/CodeMirror,d0liver/CodeMirror,elisee/CodeMirror,codio/CodeMirror,hackmdio/CodeMirror,cben/CodeMirror,djadmin/CodeMirror,skylarkcob/CodeMirror,hccampos/CodeMirror,bgrins/CodeMirror,EasonYi/CodeMirror,AlanWasTaken/codemirror,joshterrell805-historic/CodeMirror,shiren/CodeMirror,supriyantomaftuh/CodeMirror,namin/CodeMirror,Dominator008/CodeMirror,Aliccer/CodeMirror,schanzer/CodeMirror,abdelouahabb/CodeMirror,apatawari/CodeMirror,vincentwoo/CodeMirror,ksanaforge/CodeMirror,notepadqq/CodeMirror,systay/CodeMirror,NumbersInternational/CodeMirror,INTELOGIE/CodeMirror,loopspace/CodeMirror,kuangyeheng/CodeMirror,cintiamh/CodeMirror,KamranMackey/CodeMirror,axter/CodeMirror,morrisonwudi/CodeMirror,namin/CodeMirror,alur/CodeMirror,Jisuanke/CodeMirror,grzegorzmazur/CodeMirror,mtaran-google/CodeMirror,anthonygego/CodeMirror,ejgallego/CodeMirror,ssxxue/CodeMirror,ksanaforge/CodeMirror,r7kamura/CodeMirror,ssxxue/CodeMirror,kerabromsmu/CodeMirror,bgrins/CodeMirror,systay/CodeMirror,grzegorzmazur/CodeMirror,karevn/CodeMirror,flyskyko/CodeMirror,xeronith/CodeMirror,sgoo/CodeMirror,gkoberger/CodeMirror,melpon/CodeMirror,NumbersInternational/CodeMirror,pjkui/CodeMirror,abdelouahabb/CodeMirror,jkaplon/CodeMirror,ficristo/CodeMirror,qweasd1/CodeMirror,Allenice/CodeMirror,sanyaade-iot/CodeMirror,webida/CodeMirror,NeZaMy/CodeMirror2,pabloferz/CodeMirror,Dominator008/CodeMirror,bocharsky-bw/CodeMirror,isdampe/CodeMirror,Carreau/CodeMirror,trumanliu/CodeMirror,ejgallego/CodeMirror,isdampe/CodeMirror,happibum/CodeMirror-main,nightwing/CodeMirror,qiankun007/CodeMirror,ThebingServices/CodeMirror,philuchansky/CodeMirror,mightyguava/CodeMirror,matthewbauer/CodeMirror,dbarnett/CodeMirror,fmoliveira/CodeMirror,morrisonwudi/CodeMirror,nightwing/CodeMirror,apatawari/CodeMirror,kerabromsmu/CodeMirror,anthonygego/CodeMirror,vanloswang/CodeMirror,xeronith/CodeMirror,flyskyko/CodeMirror,kevinushey/CodeMirror,happibum/CodeMirror-main,rustemferreira/CodeMirror,sekcheong/CodeMirror,kolya-ay/CodeMirror,kk9599/CodeMirror,EasonYi/CodeMirror,anthonygego/CodeMirror,increpare/CodeMirror,Carreau/CodeMirror,qweasd1/CodeMirror,bocharsky-bw/CodeMirror,sourcelair/CodeMirror,bfrohs/CodeMirror,GerHobbelt/CodeMirror2,mihailik/CodeMirror,trumanliu/CodeMirror,manderson23/CodeMirror,rustemferreira/CodeMirror,jpolitz/CodeMirror,trumanliu/CodeMirror,supriyantomaftuh/CodeMirror,jayaprabhakar/CodeMirror,webida/CodeMirror,kk9599/CodeMirror,rrandom/CodeMirror,wingify/CodeMirror,crazy4chrissi/CodeMirror,antimatter15/CodeMirror,DustinH/CodeMirror,loopspace/CodeMirror,symbla/CodeMirror,kerabromsmu/CodeMirror,belph/CodeMirror,nawroth/CodeMirror,davidpham87/CodeMirror,systay/CodeMirror,bfrohs/CodeMirror,dbarnett/CodeMirror,cintiamh/CodeMirror,AlanWasTaken/codemirror,INTELOGIE/CodeMirror,DustinH/CodeMirror,gkoberger/CodeMirror,Allenice/CodeMirror,flyskyko/CodeMirror,rustemferreira/CodeMirror,karthikeyansam/CodeMirror,kangkot/CodeMirror,crazy4chrissi/CodeMirror,antimatter15/CodeMirror,thomasjm/CodeMirror,michaelerobertsjr/CodeMirror,notepadqq/CodeMirror,adobe/CodeMirror2,kuangyeheng/CodeMirror,antimatter15/CodeMirror,karthikeyansam/CodeMirror,pjkui/CodeMirror,mightyguava/CodeMirror,jpolitz/CodeMirror,pinbe/CodeMirror,dbarnett/CodeMirror,sekcheong/CodeMirror,philuchansky/CodeMirror,TechnicalPursuit/CodeMirror,davidpham87/CodeMirror,webida/CodeMirror,dudb/CodeMirror,bluesh55/CodeMirror,MarcelGerber/CodeMirror,sgoo/CodeMirror,kolya-ay/CodeMirror,qiankun007/CodeMirror,Navaneethsen/CodeMirror,mihailik/CodeMirror,vanloswang/CodeMirror,pjkui/CodeMirror,webida/CodeMirror,pabloferz/CodeMirror,ejgallego/CodeMirror,thomasjm/CodeMirror,ashmind/CodeMirror,belph/CodeMirror,namin/CodeMirror,ashmind/CodeMirror,Jisuanke/CodeMirror,d0liver/CodeMirror,sourcelair/CodeMirror,schanzer/CodeMirror,bluesh55/CodeMirror,Navaneethsen/CodeMirror,davidpham87/CodeMirror,jessegrosjean/CodeMirror,MarcelGerber/CodeMirror,EasonYi/CodeMirror,fivetran/CodeMirror,hackmdio/CodeMirror,Jisuanke/CodeMirror,agendor/CodeMirror,TechnicalPursuit/CodeMirror,ficristo/CodeMirror,sekcheong/CodeMirror,axter/CodeMirror,qiankun007/CodeMirror,r7kamura/CodeMirror,michaelerobertsjr/CodeMirror,KamranMackey/CodeMirror,Icenium/CodeMirror,rasata/CodeMirror,CartoDB/CodeMirror,loopspace/CodeMirror,ashmind/CodeMirror,adobe/CodeMirror2,bluesh55/CodeMirror,Ermlab/CodeMirror,gkoberger/CodeMirror,rasata/CodeMirror,fivetran/CodeMirror,hccampos/CodeMirror,shiren/CodeMirror,Ermlab/CodeMirror,skylarkcob/CodeMirror,michaelerobertsjr/CodeMirror,alur/CodeMirror,jpolitz/CodeMirror,SidPresse/CodeMirror,amsul/CodeMirror,InternetGuru/CodeMirror,r7kamura/CodeMirror,amsul/CodeMirror,jkaplon/CodeMirror,jkaplon/CodeMirror,pinbe/CodeMirror,agendor/CodeMirror,vanloswang/CodeMirror,ThebingServices/CodeMirror,NumbersInternational/CodeMirror,sanyaade-iot/CodeMirror,karevn/CodeMirror,NeZaMy/CodeMirror2,skylarkcob/CodeMirror,InternetGuru/CodeMirror,nawroth/CodeMirror,kuangyeheng/CodeMirror,isdampe/CodeMirror,Allenice/CodeMirror,camellhf/CodeMirror,ZombieHippie/CodeMirror,happibum/CodeMirror-main,INTELOGIE/CodeMirror,dperetti/CodeMirror,melpon/CodeMirror,amshali/CodeMirror,jayaprabhakar/CodeMirror,pabloferz/CodeMirror,vincentwoo/CodeMirror,KamranMackey/CodeMirror,tpphu/CodeMirror,tpphu/CodeMirror,cintiamh/CodeMirror