Potentially dangerous behavior when saving files

if you enter a filename in save dialogs, and prepend it with ~/ , the ~ isn't translated to the user's homedirectory, instead, a NEW directory named "~" is made in the directory ugene was started in. This is dangerous, as the new "~" is probably uhwanted, and it invites the user to enter "rm -rf ~" which would nuke the user's homedirectory. So on unix, ~ should get substituted with the user's homedirectory.