QFile::moveToTrash: use $XDG_DATA_HOME/Trash as the trash directory

The code assumed that files in $HOME should be moved into $HOME/.Trash,
which is not what the spec says. The "home trash" is defined to be
$XDG_DATA_HOME/Trash, and we can expect $XDG_DATA_HOME to exist. If it
doesn't, then we can safely fail, as the environment is not compliant
with the Desktop Base Directory Specification [1] anyway.

[1] http://www.freedesktop.org/Standards/basedir-spec

This will make the tests fail on such non-compliant environments, such
as server versions of the distribution. That's acceptable.

[ChangeLog][QtCore][QFile] moveToTrash now creates the trash folder on
Linux as $XDG_DATA_HOME/Trash, as required by the freedesktop.org spec.

Change-Id: I7ef73c0c268ef5ea4df141bb7831b93a65ad213a
Fixes: QTBUG-83933
Pick-to: 5.15
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 13 insertions, 5 deletions

diff --git a/src/corelib/io/qfilesystemengine_unix.cpp b/src/corelib/io/qfilesystemengine_unix.cpp
index 2419a01332..d91807c342 100644
--- a/src/corelib/io/qfilesystemengine_unix.cpp
+++ b/src/corelib/io/qfilesystemengine_unix.cpp
@@ -47,6 +47,9 @@
 #include <QtCore/qoperatingsystemversion.h>
 #include <QtCore/private/qcore_unix_p.h>
 #include <QtCore/qvarlengtharray.h>
+#ifndef QT_BOOTSTRAPPED
+# include <QtCore/qstandardpaths.h>
+#endif // QT_BOOTSTRAPPED
 
 #include <pwd.h>
 #include <stdlib.h> // for realpath()
@@ -1212,6 +1215,7 @@ static QString freeDesktopTrashLocation(const QString &sourcePath)
                         | QFileDevice::WriteOwner
                         | QFileDevice::ExeOwner;
         QString targetDir = topDir.filePath(trashDir);
+        // deliberately not using mkpath, since we want to fail if topDir doesn't exist
         if (topDir.mkdir(trashDir))
             QFile::setPermissions(targetDir, ownerPerms);
         if (QFileInfo(targetDir).isDir())
@@ -1227,11 +1231,11 @@ static QString freeDesktopTrashLocation(const QString &sourcePath)
     };
 
     QString trash;
-    const QLatin1String dotTrash(".Trash");
     const QStorageInfo sourceStorage(sourcePath);
     const QStorageInfo homeStorage(QDir::home());
     // We support trashing of files outside the users home partition
     if (sourceStorage != homeStorage) {
+        const QLatin1String dotTrash(".Trash");
         QDir topDir(sourceStorage.rootPath());
         /*
             Method 1:
@@ -1288,13 +1292,17 @@ static QString freeDesktopTrashLocation(const QString &sourcePath)
          file into the user's “home trash” or refuse to trash it."
 
          We trash the file into the user's home trash.
+
+        "Its name and location are $XDG_DATA_HOME/Trash"; $XDG_DATA_HOME is what
+        QStandardPaths returns for GenericDataLocation. If that doesn't exist, then
+        we are not running on a freedesktop.org-compliant environment, and give up.
     */
     if (trash.isEmpty()) {
-        QDir topDir = QDir::home();
-        trash = makeTrashDir(topDir, dotTrash);
+        QDir topDir = QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation);
+        trash = makeTrashDir(topDir, QLatin1String("Trash"));
         if (!QFileInfo(trash).isDir()) {
-            qWarning("Unable to establish trash directory %s in %s",
-                     dotTrash.latin1(), topDir.path().toLocal8Bit().constData());
+            qWarning("Unable to establish trash directory in %s",
+                     topDir.path().toLocal8Bit().constData());
         }
     }