Petascope_Rasql error message lost from invalid WCPS query

[Bang Pham Huu]

This WCPS query

for $c in (test_mean_summer_airtemp) return encode($c[Lat(200 + 200), Long(120)], "json")

and just return

<ows:Exception exceptionCode="RasdamanRequestFailed">
        <ows:ExceptionText>Error evaluating rasdaman query: 'SELECT encode(c[2:9,110.0 / 2], "json" ) FROM test_rgb AS c'</ows:ExceptionText>

without error as same as from Rasql

rasql -q 'select c[2:9,110.0 / 2] from mr2 as c' --out string

...rasdaman error 390: 

`Execution error 390 in line 1, column 9, near token [: Minterval dimension specifications must be either of type interval or integer.`