Why does this error occur when searching in web2py

Question

Possible bug when searching in SQLFORM.grid with order activated.

To reproduce:

1. SQLFORM.grid, advanced_search = True
2. Click a column header on the grid to activate 'order'
3. Click 'search' (with or without keyword)
4. Error as follows:

Traceback (most recent call last):
File "C:\Users\User\Desktop\web2py\gluon\restricted.py", line 219, in restricted exec(ccode, environment)
  File "C:/Users/User/Desktop/web2py/applications/bsmOnline/controllers/library.py", line 113, in <module>
  File "C:\Users\User\Desktop\web2py\gluon\globals.py", line 430, in <lambda>
    self._caller = lambda f: f()
  File "C:/Users/User/Desktop/web2py/applications/bsmOnline/controllers/library.py", line 56, in region
    create=can_add_library, editable=can_edit_library, deletable=can_delete_library)
  File "C:\Users\User\Desktop\web2py\gluon\tools.py", line 3951, in f
    return action(*a, **b)
  File "C:/Users/User/Desktop/web2py/applications/bsmOnline/models/db1.py", line 78, in library
    grid = SQLFORM.grid(query, maxtextlength=80, csv=False, **kwargs)
  File "C:\Users\User\Desktop\web2py\gluon\sqlhtml.py", line 2804, in grid
    otablename, ofieldname = order.split('~')[-1].split('.', 1)
    AttributeError: 'list' object has no attribute 'split'

Upon clicking the 'search' button, it seems that the 'order' in request .vars is transformed from string to list, such that order = 'anykey' becomes 'order = ['anykey', 'anykey'], hence, the error.

Workaround for me:

if request.vars:
    if 'order' in request.vars:
        request.vars.order = request.vars.order[0]

Can somebody please confirm or am I doing something wrong?