environment-build/export ran an unclassified recursive mkdir of the
destination's parent before SafeOutputTree validated anything. A
trailing `..` therefore created directories before it was refused, and
a regular file in the parent path surfaced as unreadable_output instead
of refusing the selection.
SafeOutputTree.create gains a createParents option that admits the
root's own syntax first, then creates the parents, mapping EEXIST and
ENOTDIR to a destination refusal. The environment bundle writer uses it
instead of its own mkdir.
Fixes#7688Fixes#7571
The non-directory mapping comes from #7734 by HeadmasterEggy, and the
syntax-first check from #7588 by harshitethic; their tests are kept.
Co-Authored-By: Avocado <headmastereggy@gmail.com>
Co-Authored-By: Harshit Sharma <66710144+harshitethic@users.noreply.github.com>
Co-Authored-By: gensokyo-dev <342580529+gensokyo-dev@users.noreply.github.com>
