Sometimes it happens that there are empty lines in the clipboard history. For example after selecting 'blank' spaces in the console.
As this can be useful for some users, i would suggest to add an option like 'prevent whitespace-only records in the clipboard history'. Another way may be an option to specify a regular expression for records, that should not be included in the history, which would offer greater flexibility.

Reproducible: Always

Steps to Reproduce:
1. copy or select a blank line (for example an 'empty space' in the Konsole)
2. 
3.
Actual Results:  
new record appears in the clipboard history, that contains only whitespaces