Attempting to access font attribute of existing cell with default formatting causes error
*Created originally on Bitbucket by [jordan_macdonald (Jordan Macdonald)](https://bitbucket.org/%7B4e8e639d-5f93-4b5b-9c1f-f2d20eced5f3%7D/)*
One of my scripts which uses openpyxl to read data from an existing spreadsheet has stopped working after I upgraded to 2.3. The error occurs when I try to access the font property of a cell in order to check that it is not struck-through (strike-through being used to flag a cell to be skipped). The relevant section of the stack trace:
```
File "C:\Users\jordan_macdonald\[REDACTED]", line 27, in __init__
if (cell is None or cell.value is None or cell.font.strike):
File "C:\Python27\lib\site-packages\openpyxl-2.3.0b2-py2.7.egg\openpyxl\cell\read_only.py", line 81, in font
_id = self.style_array.fontId
AttributeError: 'NoneType' object has no attribute 'fontId'
```
Other than the possible strike-through, the cell in question is has no formatting specified in the source spreadsheet; I presume the error is caused because the new style management code fails to specify a default Font object for cells in the default format.
*Attachments:* [err.py](/uploads/7784ae67de55fc3680926c06dddd6774/err.py)[err.xlsx](/uploads/82eac86a755b5ed8342efaeabd8a2f43/err.xlsx)
issue