Description:
Automatic filter doesn't work when a column has got multiple formats in its cells. 

For example, we've got a column with some dates and other texts. If you filter usings months, it doesn't filter nothing. I attach a file with an example.

I couldn't determine initial version where to reproduce the problem, but it doesn't happened in version 5.0.5. We have reproduce it with LOCalc 5.2.6 (windows 64 bits) and 5.3.1.2 (Linux 64bits)

Steps to Reproduce:
1.Select title row. Data -> Automatic filter
2.Select column where are data formats mixed. Select filter
3. Unselect all and select only one month in a year

Actual Results:  
It doesn't show nothing

Expected Results:
It has to show what you have selected (rows with that month/year)


Reproducible: Always

User Profile Reset: No

Additional Info:


User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.98 Safari/537.36 OPR/44.0.2510.857