Fix buffer pure mode regression.
Fix buffer pure mode regression.

roxyboy/cython,scoder/cython,c-blake/cython,dahebolangkuan/cython,madjar/cython,JelleZijlstra/cython,mcanthony/cython,ABcDexter/cython,dahebolangkuan/cython,fabianrost84/cython,achernet/cython,mcanthony/cython,c-blake/cython,cython/cython,madjar/cython,andreasvc/cython,roxyboy/cython,fperez/cython,scoder/cython,marscher/cython,mrGeen/cython,encukou/cython,encukou/cython,acrispin/cython,achernet/cython,scoder/cython,hhsprings/cython,hhsprings/cython,ChristopherHogan/cython,cython/cython,ABcDexter/cython,acrispin/cython,JelleZijlstra/cython,c-blake/cython,fperez/cython,ABcDexter/cython,scoder/cython,da-woods/cython,fperez/cython,marscher/cython,acrispin/cython,hickford/cython,mcanthony/cython,madjar/cython,hhsprings/cython,madjar/cython,dahebolangkuan/cython,ChristopherHogan/cython,c-blake/cython,da-woods/cython,roxyboy/cython,achernet/cython,andreasvc/cython,fperez/cython,hickford/cython,mrGeen/cython,mrGeen/cython,slonik-az/cython,hickford/cython,da-woods/cython,slonik-az/cython,ChristopherHogan/cython,encukou/cython,mcanthony/cython,andreasvc/cython,slonik-az/cython,achernet/cython,acrispin/cython,da-woods/cython,fabianrost84/cython,fabianrost84/cython,fperez/cython,fabianrost84/cython,hhsprings/cython,encukou/cython,JelleZijlstra/cython,hickford/cython,hhsprings/cython,JelleZijlstra/cython,ABcDexter/cython,cython/cython,encukou/cython,slonik-az/cython,mrGeen/cython,cython/cython,andreasvc/cython,JelleZijlstra/cython,fabianrost84/cython,mcanthony/cython,madjar/cython,dahebolangkuan/cython,slonik-az/cython,roxyboy/cython,achernet/cython,marscher/cython,ABcDexter/cython,marscher/cython,roxyboy/cython,andreasvc/cython,acrispin/cython,mrGeen/cython,c-blake/cython,hickford/cython,marscher/cython,dahebolangkuan/cython