fix 2315 by checking scale == 0
fix 2315 by checking scale == 0

dhomeier/astropy,MSeifert04/astropy,kelle/astropy,pllim/astropy,AustereCuriosity/astropy,lpsinger/astropy,larrybradley/astropy,AustereCuriosity/astropy,joergdietrich/astropy,kelle/astropy,mhvk/astropy,bsipocz/astropy,larrybradley/astropy,bsipocz/astropy,saimn/astropy,mhvk/astropy,funbaker/astropy,stargaser/astropy,StuartLittlefair/astropy,MSeifert04/astropy,aleksandr-bakanov/astropy,bsipocz/astropy,pllim/astropy,joergdietrich/astropy,StuartLittlefair/astropy,DougBurke/astropy,saimn/astropy,dhomeier/astropy,AustereCuriosity/astropy,larrybradley/astropy,AustereCuriosity/astropy,MSeifert04/astropy,joergdietrich/astropy,astropy/astropy,dhomeier/astropy,DougBurke/astropy,astropy/astropy,stargaser/astropy,astropy/astropy,lpsinger/astropy,funbaker/astropy,dhomeier/astropy,stargaser/astropy,mhvk/astropy,astropy/astropy,dhomeier/astropy,saimn/astropy,joergdietrich/astropy,pllim/astropy,mhvk/astropy,aleksandr-bakanov/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,lpsinger/astropy,lpsinger/astropy,StuartLittlefair/astropy,tbabej/astropy,tbabej/astropy,kelle/astropy,StuartLittlefair/astropy,kelle/astropy,DougBurke/astropy,aleksandr-bakanov/astropy,pllim/astropy,tbabej/astropy,stargaser/astropy,bsipocz/astropy,MSeifert04/astropy,DougBurke/astropy,tbabej/astropy,AustereCuriosity/astropy,funbaker/astropy,pllim/astropy,mhvk/astropy,kelle/astropy,joergdietrich/astropy,saimn/astropy,tbabej/astropy,larrybradley/astropy,StuartLittlefair/astropy,saimn/astropy,astropy/astropy,lpsinger/astropy,funbaker/astropy