Handling of chrooted STOU causes incorrect permissions

[Castaglia]

Per Bug#4223, the mod_xfer module was not correctly honoring the Umask directive for files uploaded using the STOU command. This has been fixed.

However, the user who reported this issue still saw the problem because their proftpd was using the mod_vroot module. Specifically, the resolving of the path for the ultimate chmod(2) system call was failing, as the resolved path included a leading "/" -- and this lead to the ENOENT error.

[Castaglia]

One workaround, tested, was to see if the given path, in the vroot_chmod() function, is a relative or absolute path. If a relative path, make it an absolute path by prefixing pr_fs_getvwd(), then calling vroot_lookup_path() on the resulting absolute path; this worked as expected.