viewproperties: detect read-only directories on Windows

On Windows QFileInfo::isWritable() returns true for a directory that
carries the read-only attribute, because the attribute does not prevent
creating child files. It does prevent writing the directory's own
extended attribute, the Alternate Data Stream where the view properties
are stored, so the save fails with access denied and the settings are
lost.

Detect the read-only attribute with GetFileAttributesW and store the view
properties in the destination directory instead, the same way a directory
without write permission is handled on other platforms.

The read-only directory test checks that the properties land in the
destination directory.

0 files changed, 0 insertions, 0 deletions