Update common.py
Force violate array to be of type int. When no nan values are found, the array defaults to an empty array of type float, so you get an error: **\* IndexError: arrays used as indices must be of integer (or boolean) type

need a test for this
does this fix sn open issue?
can u show what exactly the problem is?
 Sorry for not adding a test. I didn't report an issue or looked for an open one. Just fixed it straight away. See a simple testcase below:

``` python
from pandas import DataFrame
from numpy import NaN
df = DataFrame({'A': [1,2,3,5]})

# interpolation with 'limit' argument gives error when there are no nan values in the series:
df.interpolate(limit=1)

# after adding a NaN value, no error
df.loc[1] = NaN
df.interpolate(limit=1)
```
 @tdamsma your example above would need to be incorporated in this PR as a test, see here: https://github.com/pydata/pandas/wiki/Testing
 @tdamsma your example looks correct to me. closing this. pls create an issue showing what the bug actually is.
