Clarify the expected variables start/count behavior #571
Description
Currently, the specification doesn't describe the expected DAP server behavior when the start or count in the Variables request is out of range.
Some debuggers return an error when the count is greater than the number of available variables, others return fewer variables than requested.
Similarly, different DAP server interpret the namedVariables and indexedVariables fields in the Variable type differently.
Some of them return non-zero variablesReference with a zero namedVariables (indexedVariables is absent).
The non-zero variablesReference suggests that children can be retrieved.
The zero namedVariables suggests that the variable has no children.
Could you please add the expected behavior/contract to the specification?
I believe it will make writing a generic DAP client easier.