'delphin process' generation doesn't work without 'where' condition

[goodmami]

Trying to generate with delphin process leads to a TSQLSyntaxError:

$ delphin process -g erg-2018-x86-64-0.9.31.dat -e -s mrs/ mrs-gen

  line 1
    * from item where .
                      ^
TSQLSyntaxError: expected one of: '!' or 'not', (, a qualified identifier, a simple identifier

The problem is that the process code constructs a temporary profile and builds a TSQL where condition defaulting to '' if there is none. But the mkprof code does not consider '' to be no condition, only None, so it makes an empty where clause:

pydelphin/delphin/commands.py

Line 458 in fe91451

where = '' if where is None else 'where ' + where

The workaround is to give an explicit where clause in the --select option, e.g.:

$ delphin process -g erg-2018-x86-64-0.9.31.dat -e -s mrs/ mrs-gen --select='mrs where result-id=0'

Changing the if where is None part of the above code snippet to if not where seems to fix the issue.