Fixed crash in CTLineUtils
Fixed crash in CTLineUtils

Cocoanetics/DTCoreText,programming086/DTCoreText,xiaoyanit/DTCoreText,Akylas/DTCoreText,Cocoanetics/DTCoreText,openresearch/DTCoreText,Cocoanetics/DTCoreText,Akylas/DTCoreText,pivotaltracker/DTCoreText,rgregg/DTCoreText,gnr/DTCoreText,rgregg/DTCoreText