This is a patch from Vladimir:

This is a patch from Vladimir:

    > I rewrite *local_variable* function in hush.c with:
    > 1) remove many memory leaks
    > 2) add support read_only protect (require write builtin function for set this,
    > I write this special for variable HUSH_VERION=0.01)
    > 3) commad read set only local variable now
    > 4) remove many error messages if "set unset export" not defined variable
    > (bash syntax not put and set error code). Hmm, if I set result to -1, you hush
    > called waitpid and returned with error "no waitpid" ( i not found place this
    > error).
    > 5) destroy error in new version check xgetcwd()==NULL and set "(unknow)" -
    > this have error: crashe in next call `pwd`, but xgetcwd(not null) called
    > free(arg).
    > 6) next add integraion with libbb

Valdimir's patch missed two cases of local variable handling
    FOO=bar
    export FOO=baz
    unset FOO
and
    export FOO=bar
    FOO=baz
which were working before, so I fixed those two cases.