Querying for modalities does not filter for sessions or subjects

[Remi-Gau]

Example from the 7T-trt dataset from bids-example

$ tree -d sub-0[12]
sub-01
├── ses-1
│   ├── anat
│   ├── fmap
│   └── func
└── ses-2
    ├── fmap
    └── func
sub-02
├── ses-1
│   ├── anat
│   ├── fmap
│   └── func
└── ses-2
    ├── fmap
    └── func

Actual behavior

BIDS = bids.layout(dataset_path);
bids.query(BIDS,  'modalities',  'sub',  '01',  'ses',  '2')

ans =

  1×3 cell array

    'anat'    'func'    'fmap'

Expected behavior

BIDS = bids.layout(dataset_path);
bids.query(BIDS,  'modalities',  'sub',  '01',  'ses',  '2')

ans =

  1×2 cell array

   'func'    'fmap'

Notes

This also applies to spm_bids

[gllmflndn]

Confirmed. It is similar to #12: subjects, sessions and modalities were dealt with differently than the other keywords - they are qualitatively different but it seems that the code path can be the same. modalities is the last one treated separately.
I will open a pull request with a potential fix.

[Remi-Gau]

Fixed by PR #71