PHPOffice/PHPExcel — pull request #212 by IndrekHaav (2013-07-08 23:42:59+00:00)
Title: Fixed undefined variable error due to $styleArray being used before it's initialised

Ran across the same issue reported two years ago on Codeplex:
http://phpexcel.codeplex.com/workitem/16208

Seemed like a simple fix.