Fixed bug with when CTRunGetGlyphsPtr returns NULL
Fixed bug with when CTRunGetGlyphsPtr returns NULL

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