I've made tiny changes in my test script. You can find out everything
in the attachment (i.e. every my message with attachment is suitable
to possible commit, if it will be reviewed).

My test script is separate *.exp file but I don't sure that it's right.
To test I just run:

... gdb-7.2/gdb/testsuite$ runtest --all gdb.base/bt-nopath.exp

Is everything ok? Or what I should change?