Assigning to myself to submit a regression test:

 darcs mv inkscape-layers* inkscape-layers

complains that the target directory "inkscape-layers.hs" (note the hs)
does not exist

The real reason this happens (I think) is that if you expand that glob,
you get something like

 darcs mv inkscape-layers inkscape-layers.cabal inkscape-layers.hs
inkscape-layers

Somewhere that second inkscape-layers gets filtered out and this becomes
equivalent to saying

 darcs mv inkscape-layers inkscape-layers.cabal inkscape-layers.hs

Oops.  I'm hoping this is just superficially on the Darcs.Commands.Move
layer and not something deeper that's simplifying those command lines.

Assigning to myself to produce a regression test.

I'm about to push my test case into the darcs.net repository.  I guess
the point is that

  darcs mv d d.txt d

should actually complain that you're trying to mv d onto itself and not
fool itself into thinking that you're just doing

  darcs mv d d.txt

Seems like a straightforward fix to make.

The following patch sent by bsrkaditya@gmail.com updated issue issue1737 with
status=resolved;resolvedin=2.8.0 HEAD

* resolve issue1737: darcs mv does not warn when moving old to new if > 2 args 
Ignore-this: acb803e02ad9cbf10a835f3c187a92a2