Nyall Dawson 1c1de3a88b [processing] Fix optional numeric parameters cannot be cleared
Without this change optional numeric parameters have no way to
be cleared in the GUI - they are always forced to have a value

Fixes #17471 - but I've noticed that many optional numeric
GRASS parameters have a non-null default value. These may
need to be investigated and manually changed to None defaults
in the description files.
2017-12-01 20:42:38 +11:00
..