BUG: tsorter fails to sort sequence BLAST links

[ChrisKeefe]

Bug Description
tsorter, the sort script used on visualizations produced by feature-table tabulate-seqs, fails to sort sequence links in an expected manner. Other column headers, when clicked, produce clean alphabetical sorts, but the "Sequence" column does not.

Steps to reproduce the behavior

1. Open a .qzv produced by feature-table tabulate-seqs. (e.g. Moving Pictures)
2. Click on column header "Sequence". Note that sequences alternate between "TACGT..." and "TACGG..." intermittently as you scroll.
3. Click on the same column header again. Note the same behavior when sorted in reverse.
4. Click on the "Feature ID" column header. Nice, clean sort.

Expected behavior
When user clicks the Sequence header, sequences sort alphabetically.

Computation Environment
Failure to sort appears on both OSX v? and LinuxMint 18.3 Cinnamon

Comments

1. The problematic column contains a series of hrefs to NCBI BLAST. I have experimented with tsorter's data-tsorter="link" attribute, with no improvement in functionality. YMMV.
2. If it proves easiest to replace tsorter here, the column sorter used in q2-metadata metadata-tabulate may be an option.

References

1. Moving Pictures viz from feature-table tabulate-seqs
2. Moving Pictures vis from q2-metadata metadata-tabulate
3. source html for feature-table tabulate-seqs vis