Append user data to the new arguments array, not the source one
Append user data to the new arguments array, not the source one

This code was previously adding a new item to the passed in array
instead of appending it to the newly created array, causing a buffer
overflow that sometimes ends in stack corruption and a crash.

https://bugzilla.gnome.org/show_bug.cgi?id=695876

danilocesar/seed,danilocesar/seed,danilocesar/seed,danilocesar/seed,danilocesar/seed