Casey..
Rob is right..cut it at the leak..clean up both ends and put a compression fitting on and bobs your uncle..
barring that..and I am a refrigeration mechanic and deal with high pressure gas leaks for the last 45 years..and have used all kinds of methods to fix all kinds of leaks in all kinds of materials with all kind of fluids and gasses..so have a little experience..
My next suggestion and it would be quick is to stick weld it with eutectic 7018..
Try a bead a few inches away from the hole and test out your bead..once you are laying a nice bead start outside the crack and weld your bead right over the crack..give the bead a few extra mm from the end of the crack..undo your battery before you try to weld in place and if you can take the line off remove it and do it on the bench..other wise if not possible to remove undo one end or the pressure caused by the heat will blow out the weld.along with a bunch of flaming gasoline.
Or whatever is in the line..
Maybe I would pre heat the line to be safe ..have a fire extinguisher handy..
Good luck..
Don't use soft solder unless you know what you are doing..a soft low temp silver solder that will stick to steel or stainless is available called Easy flo..used in the refrigeration industry..17000Pounds tensile strength so ideal for the job..I would use that because I have it..have been using it for years and would not use so much that it would run into the pipe and plug it..a problem when using easyflo..amateur mistake..
Good luck..If you have a buddy refrigeration mechanic..he could fix that up in no time..
Good luck.
Merry Christmas..
here is some cowboy Christmas music to enjoy a little Brit humour..
http://www.youtube.com/watch?v=7VRw_...e_gdata_player