The new registration of in-process data filters (introduced in
75177cef51d3 & 8c9fa240ac96) failed to correctly strip the filter name
from its arguments before passing the "command" to the filter
function. Thus a registration such as
[decode]
*.gz = compress: -9
would result in the associated filter function being called with the
argument 'compress: -9' rather than just '-9' as expected.
