[GRASS5] 5.7: dbf driver and 'double' initialization

[Markus Neteler]

There seems to be a problem with the initialization of
double (maybe also int) type in the DBF driver of 5.7:

echo "ALTER TABLE dourokukan ADD COLUMN forward double" | db.execute
echo "ALTER TABLE dourokukan ADD COLUMN backward double" | db.execute
echo "ALTER TABLE dourokukan ADD COLUMN length double" | db.execute

dbfdump dourokukan.dbf
        cat label      forward             backward              length
          1 s3m        (NULL)               (NULL)               (NULL)
          3 e3.0m      (NULL)               (NULL)               (NULL)
          5 e5.5m      (NULL)               (NULL)               (NULL)
         13 s13.0      (NULL)               (NULL)               (NULL)
         15 yes        (NULL)               (NULL)               (NULL)

I assume that it should be set to zero (0).
At least I don't know how to access these (NULL) values in
a later SQL update :

echo "UPDATE dourokukan SET forward=50 WHERE forward=0" | db.execute
echo "SELECT * FROM dourokukan" | db.select
cat|label|forward|backward|length
1|s3m|||
3|e3.0m|||
5|e5.5m|||
13|s13.0|||
15|yes|||

Any advice is welcome,

 Markus