Blank resolution causing problems

[Gervase Markham]

Developers,

The use of the value "" for "no resolution" is causing problems in 
charting. The charting code is pretty generic (it has to be, to cope 
with arbitrary charts) but if this value is to be used in labels, it 
needs special-casing everywhere.

For some of the problems using "" causes, see:
https://bugzilla.mozilla.org/show_bug.cgi?id=289697
https://bugzilla.mozilla.org/show_bug.cgi?id=289694
https://bugzilla.mozilla.org/show_bug.cgi?id=289691

This fairly old line from query.cgi also tells its own story:

push @::legal_resolution, "---"; # Oy, what a hack.

This is needed to allow it to distinguish between "specifically, there 
is no resolution" and "I don't want to specify any restrictions on the 
value of the resolution".

Would it be reasonable to update Bugzilla to use a string like "[None]" 
to represent no resolution? Or is there another, better solution to this 
problem? (Using "NULL" in the database instead of "" may make database 
purists happier, but doesn't solve this problem as far as I can see.)

Gerv