pydata/pandas — pull request #8176 by jreback (2014-09-04 18:11:29+00:00)
Title: BUG/API: Previously an enlargement with a mixed-dtype frame would act unlike append (related GH2578)

related #2578

from [SO](http://stackoverflow.com/questions/25670760/copying-a-row-screws-up-pandas-column-data-types-how-to-avoid)