correct trig_split: factoring does not remove -1 from -x-y
correct trig_split: factoring does not remove -1 from -x-y

amitjamadagni/sympy,Vishluck/sympy,mcdaniel67/sympy,Davidjohnwilson/sympy,meghana1995/sympy,Arafatk/sympy,hrashk/sympy,VaibhavAgarwalVA/sympy,atsao72/sympy,debugger22/sympy,shipci/sympy,ahhda/sympy,vipulroxx/sympy,debugger22/sympy,abhiii5459/sympy,yukoba/sympy,dqnykamp/sympy,sunny94/temp,Shaswat27/sympy,jbbskinny/sympy,pbrady/sympy,bukzor/sympy,yashsharan/sympy,aktech/sympy,Curious72/sympy,abhiii5459/sympy,yukoba/sympy,kaichogami/sympy,ga7g08/sympy,shikil/sympy,hargup/sympy,lidavidm/sympy,Designist/sympy,jaimahajan1997/sympy,jerli/sympy,sahmed95/sympy,shipci/sympy,iamutkarshtiwari/sympy,diofant/diofant,atreyv/sympy,cccfran/sympy,garvitr/sympy,Gadal/sympy,jamesblunt/sympy,atsao72/sympy,Arafatk/sympy,VaibhavAgarwalVA/sympy,hargup/sympy,sunny94/temp,liangjiaxing/sympy,grevutiu-gabriel/sympy,pandeyadarsh/sympy,rahuldan/sympy,mcdaniel67/sympy,wanglongqi/sympy,lindsayad/sympy,Sumith1896/sympy,debugger22/sympy,pbrady/sympy,mcdaniel67/sympy,Sumith1896/sympy,sahmed95/sympy,kumarkrishna/sympy,oliverlee/sympy,postvakje/sympy,maniteja123/sympy,garvitr/sympy,emon10005/sympy,pbrady/sympy,AkademieOlympia/sympy,Titan-C/sympy,sampadsaha5/sympy,MechCoder/sympy,postvakje/sympy,kaichogami/sympy,lindsayad/sympy,moble/sympy,toolforger/sympy,abloomston/sympy,souravsingh/sympy,lidavidm/sympy,beni55/sympy,rahuldan/sympy,Shaswat27/sympy,farhaanbukhsh/sympy,aktech/sympy,dqnykamp/sympy,hrashk/sympy,sahilshekhawat/sympy,jaimahajan1997/sympy,atreyv/sympy,Curious72/sympy,Gadal/sympy,sampadsaha5/sympy,lindsayad/sympy,toolforger/sympy,AunShiLord/sympy,ChristinaZografou/sympy,maniteja123/sympy,Mitchkoens/sympy,ahhda/sympy,sahilshekhawat/sympy,yashsharan/sympy,MridulS/sympy,Vishluck/sympy,liangjiaxing/sympy,jamesblunt/sympy,Shaswat27/sympy,meghana1995/sympy,abloomston/sympy,abloomston/sympy,toolforger/sympy,oliverlee/sympy,skidzo/sympy,shikil/sympy,Mitchkoens/sympy,sahilshekhawat/sympy,drufat/sympy,wyom/sympy,jerli/sympy,Vishluck/sympy,amitjamadagni/sympy,abhiii5459/sympy,kevalds51/sympy,shikil/sympy,wanglongqi/sympy,maniteja123/sympy,sunny94/temp,cccfran/sympy,asm666/sympy,beni55/sympy,skirpichev/omg,madan96/sympy,yukoba/sympy,Curious72/sympy,Titan-C/sympy,skidzo/sympy,iamutkarshtiwari/sympy,Davidjohnwilson/sympy,liangjiaxing/sympy,drufat/sympy,yashsharan/sympy,VaibhavAgarwalVA/sympy,Titan-C/sympy,vipulroxx/sympy,oliverlee/sympy,jaimahajan1997/sympy,chaffra/sympy,saurabhjn76/sympy,Davidjohnwilson/sympy,farhaanbukhsh/sympy,AunShiLord/sympy,ahhda/sympy,kevalds51/sympy,bukzor/sympy,cccfran/sympy,Sumith1896/sympy,atreyv/sympy,kaichogami/sympy,garvitr/sympy,cswiercz/sympy,shipci/sympy,saurabhjn76/sympy,kmacinnis/sympy,bukzor/sympy,farhaanbukhsh/sympy,asm666/sympy,beni55/sympy,saurabhjn76/sympy,grevutiu-gabriel/sympy,hrashk/sympy,kevalds51/sympy,pandeyadarsh/sympy,souravsingh/sympy,MechCoder/sympy,MridulS/sympy,kmacinnis/sympy,sampadsaha5/sympy,kmacinnis/sympy,cswiercz/sympy,dqnykamp/sympy,sahmed95/sympy,madan96/sympy,souravsingh/sympy,pandeyadarsh/sympy,wyom/sympy,Arafatk/sympy,AunShiLord/sympy,kumarkrishna/sympy,aktech/sympy,jamesblunt/sympy,Mitchkoens/sympy,kaushik94/sympy,jbbskinny/sympy,kaushik94/sympy,meghana1995/sympy,atsao72/sympy,kaushik94/sympy,vipulroxx/sympy,Designist/sympy,lidavidm/sympy,MridulS/sympy,mafiya69/sympy,grevutiu-gabriel/sympy,ChristinaZografou/sympy,rahuldan/sympy,wanglongqi/sympy,wyom/sympy,skidzo/sympy,hargup/sympy,chaffra/sympy,chaffra/sympy,madan96/sympy,postvakje/sympy,AkademieOlympia/sympy,mafiya69/sympy,moble/sympy,Designist/sympy,mafiya69/sympy,jerli/sympy,ga7g08/sympy,ChristinaZografou/sympy,asm666/sympy,jbbskinny/sympy,AkademieOlympia/sympy,ga7g08/sympy,emon10005/sympy,MechCoder/sympy,iamutkarshtiwari/sympy,Gadal/sympy,moble/sympy,emon10005/sympy,kumarkrishna/sympy,drufat/sympy,cswiercz/sympy