Temporary paths coming from the environment must be real filesystem
things, never a Qt file engine, so we don't need to create QDir with its
QDirPrivate, in order to call QFileSystemEngine.
The replacing of canonicalPath() with QFSE::absoluteName() is fine
because canonicalizing *after* cleanPath() is the wrong thing. For
example, if you had:
$ ln -s $HOME/tmp /tmp/symlink
$ TMPDIR=/tmp/symlink/..
then
cleanPath($TMPDIR) = /tmp
absolute($TMPDIR) = /tmp # QFSE::absoluteName calls cleanPath
canonical($TMPDIR) = $HOME
canonical(cleanPath($TMPDIR)) = /tmp
The lack of canonicalization now only affects when the final path is a
symlink. Doing so bought us little security if it is a symlink and it
could change, because the result is not cached and could change from
call to call. That changing is probably worse than any attack, because
you could end up with
QDir::tempPath() != QDir::tempPath()
[ChangeLog][QtCore][QDir] tempPath() may now return a non-canonical
path. This means going up from it (cdUp()) may result in different paths
from string manipulation (adding "/..").
Pick-to: 6.10 6.9
Change-Id: Iddf6f46edf6f3b6c3222fffd1e1e5479f0be92a9
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
7bd7df5aa1