#94 Writing metadata xattr on directories with sticky bit set

[Ralph Böhme]

Even though we may have write access to a directory, if the sticky bit is set only the owner is allowed to write xattrs.

Add an option that enables behaviour to set the xattr as root, using the fact that we can distinguish between a failing xattr set request due to insufficient permissions (EACCES) or the sticky bit (EPERM).

force xattr with sticky bit = yes|no (default: no)

[Ralph Böhme]

Implemented in [3a84db87064922ad10ac10cc1d6833380e575995] for 3.1.4.