WCS scaling extension wrongly maps scale-factor to WCPS

[Piero Campalani]

WCS scaling extensions makes a wrong mapping to WCPS query in case of scale factors, turning lo and hi bounds to lo/factor and hi/factor bounds, but this breaks when lo or hi are 0 since the

service=WCS&
version=2.0.1&
request=GetCoverage&
coverageId=mr&
subset=i(0,7)&
subset=j(0,7)&
scalefactor=0.1

becomes:

select csv(scale( c[0:7,203:210], [0:70,2030:2100] )) from mr AS c

but the index extent then is scaled from 8 to 71 cells, while it should go to 80 cells.

[Piero Campalani]

Proper scaling is on the lo/hi extent: fix upcoming.

[Piero Campalani]

a note: this does not actually depend on the index values (0 or not).
The current implementation scales the single bounds but this does never work since the formula of the extent includes the +1 term:

EXTENT := (hi - lo) + 1 = W

SCALED_EXTENT := EXTENT/F
              := [(hi - lo) + 1]/F = W/F
              := [(hi/F - lo/F) + 1/F]

whereas the current implementation yields an extent of [(hi/F - lo/F) + 1].

[Piero Campalani]

Fixed in changeset:3763e65.