Problem with filenames beginning with - (Windows only?)

for file name called -.sh on windows I got this error
'''
.....\repo>gin upload -- .-sh
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x10 pc=0x74f4c6]

goroutine 21 [running]:
github.com/G-Node/gin-cli/git.filterpaths.func1(0x11c100e0, 0x4, 0x0, 0x0, 0x90c9a0, 0x11d20ea0, 0x20, 0x829600)
/home/achilleas/code/go/src/github.com/G-Node/gin-cli/git/util.go:110 +0x56
path/filepath.Walk(0x11c100e0, 0x4, 0x11d20e80, 0x11d3a2f4, 0x11d37270)
/usr/lib/go/src/path/filepath/path.go:402 +0x60
github.com/G-Node/gin-cli/git.filterpaths(0x11db4018, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
/home/achilleas/code/go/src/github.com/G-Node/gin-cli/git/util.go:120 +0xb6
github.com/G-Node/gin-cli/git.gitAddDirect(0x11db4018, 0x1, 0x1, 0x0, 0x0, 0x0)
/home/achilleas/code/go/src/github.com/G-Node/gin-cli/git/git.go:996 +0x1d6
github.com/G-Node/gin-cli/git.Add(0x11db4018, 0x1, 0x1, 0x11d368c0)
/home/achilleas/code/go/src/github.com/G-Node/gin-cli/git/git.go:261 +0x6d5
created by github.com/G-Node/gin-cli/ginclient.Add
/home/achilleas/code/go/src/github.com/G-Node/gin-cli/ginclient/repos.go:248 +0x1ea
'''

the same result was with command gin upload "-.sh"
upload with "gin upload ." work even with this file

VERSION: GIN command line client 1.5 Build 001238 (08c5a3d03a2111ac3b1fa99432bcf46143b7f6e3)
git: 2.20.1.windows.1
git-annex: 6.20180927-gc5b6c55af