Multiselect sends null value even if option is selected

[mvdbeek]

Unclear how exactly the user has done this, but this parameter definition

        <param name="overlap_mode" type="select" multiple="true" label="What should be written to the output file?">
            <option value="-wa">
                Write the original entry in A for each overlap (-wa)
            </option>
            <option value="-wb">
                Write the original entry in B for each overlap. Useful for knowing what A overlaps. Restricted by the fraction- and reciprocal option (-wb)
            </option>
            <option value="-wo">
                Write the original A and B entries plus the number of base pairs of overlap between the two features. Only A features with overlap are reported. Restricted by the fraction- and reciprocal option (-wo)
            </option>
            <option value="-wao">
                Write the original A and B entries plus the number of base pairs of overlap between the two features. However, A features w/o overlap are also reported with a NULL B feature and overlap = 0. Restricted by the fraction- and reciprocal option (-wao)
            </option>
            <option value="-loj">
                Perform a "left outer join". That is, for each feature in A report each overlap with B.  If no overlaps are found, report a NULL feature for B (-loj)
            </option>
        </param>

from bedtools intersect
led to:

TypeError: sequence item 0: expected str instance, NoneType found
  File "galaxy/web/framework/decorators.py", line 346, in decorator
    rval = func(self, trans, *args, **kwargs)
  File "galaxy/webapps/galaxy/api/tools.py", line 247, in build
    return tool.to_json(trans, kwd.get("inputs", kwd), history=history)
  File "galaxy/tools/__init__.py", line 2509, in to_json
    populate_state(request_context, self.inputs, params.__dict__, state_inputs, state_errors)
  File "galaxy/tools/parameters/__init__.py", line 412, in populate_state
    _populate_state_legacy(
  File "galaxy/tools/parameters/__init__.py", line 625, in _populate_state_legacy
    check_param(request_context, input, param_value, context, simple_errors=simple_errors)
  File "galaxy/tools/parameters/__init__.py", line 246, in check_param
    value = param.from_json(value, trans, param_values)
  File "galaxy/tools/parameters/basic.py", line 1045, in from_json
    f"invalid options ({','.join(set(value) - set(legal_values))!r}) were selected (valid options: {','.join(legal_values)})",

where value is

[None,  '-wb']

I can partially fix this on the backend so that a proper error is returned, however this selection is wrong and needs to be fixed on the client.

[mvdbeek]

Figured it out, click on switch to column select before interacting with the values, and see that 1 items is already selected, I suppose that's null:

[ahmedhamidawan]

Figured it out, click on switch to column select before interacting with the values, and see that 1 items is already selected, I suppose that's null

Oh, I think this part is fixed in #17990

[mvdbeek]

Fixed in #17990 & #18002