QFile::moveToTrash/Unix: ensure we try to remove the proper source

We already had code to strip ending slashes, which makes sense if trying
to trash directories. In the case of symlinks to directories, that also
changes from trashing the directory to trashing the symlink. But had to
removeFile() on the same modified path.

Fixes: QTBUG-126621
Pick-to: 6.7
Change-Id: I46feca3a447244a8ba19fffd17dc0b56f2b1c68c
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 3302b0cdc15995fb9e70cf9e911d3ab408691b42)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/io/qfile.cpp

@@ -462,7 +462,9 @@ QFile::remove(const QString &fileName)
 //! [move-to-trash-common]
     The time for this function to run is independent of the size of the file
     being trashed. If this function is called on a directory, it may be
-    proportional to the number of files being trashed.
+    proportional to the number of files being trashed. If the current
+    fileName() points to a symbolic link, this function will move the link to
+    the trash, possibly breaking it, not the target of the link.
 
     This function uses the Windows and \macos APIs to perform the trashing on
     those two operating systems. Elsewhere (Unix systems), this function

src/corelib/io/qfilesystemengine_unix.cpp

@@ -1531,7 +1531,7 @@ bool QFileSystemEngine::moveFileToTrash(const QFileSystemEntry &source,
         renamed = renameat(op.filesDirFd, op.tempTrashFileName, op.filesDirFd,
                            QFile::encodeName(uniqueTrashedName)) == 0;
         if (renamed)
-            removeFile(source, error);  // success, delete the original file
+            removeFile(sourcePath, error);  // success, delete the original file
     }
     if (!renamed) {
         error = QSystemError(errno, QSystemError::StandardLibraryError);

tests/auto/corelib/io/qfile/tst_qfile.cpp

@@ -292,6 +292,9 @@ private slots:
     void moveToTrashDuplicateName();
     void moveToTrashOpenFile_data();
     void moveToTrashOpenFile();
+    void moveToTrashSymlinkToFile();
+    void moveToTrashSymlinkToDirectory_data();
+    void moveToTrashSymlinkToDirectory();
     void moveToTrashXdgSafety();
 
     void stdfilesystem();
@@ -4236,6 +4239,79 @@ void tst_QFile::moveToTrashOpenFile()
     }
 }
 
+void tst_QFile::moveToTrashSymlinkToFile()
+{
+#if defined(Q_OS_ANDROID) || defined(Q_OS_WEBOS) || defined(Q_OS_VXWORKS)
+    QSKIP("This platform doesn't implement a trash bin");
+#endif
+    QTemporaryFile temp(QDir::homePath() + "/tst_qfile.moveToTrashSymlinkFile.XXXXXX");
+    QVERIFY2(temp.open(), "Failed to create temporary file: " + temp.errorString().toLocal8Bit());
+
+    // Create the symlink
+    const QString linkName = temp.fileName() + ".lnk";
+    QVERIFY2(temp.link(linkName), "Failed to create link: " + temp.errorString().toLocal8Bit());
+    auto cleanLink = qScopeGuard([&]() {
+        QFile::remove(linkName);
+    });
+
+    // now trash it
+    QFile symlink(linkName);
+    QVERIFY(symlink.moveToTrash());
+    QCOMPARE_NE(symlink.fileName(), linkName);
+
+    // confirm that the target is still a symlink
+    QFileInfo fi(symlink.fileName());
+    QVERIFY(fi.isSymLink());
+    QVERIFY(fi.isFile());   // we used an absolute path, so it should not be broken!
+    symlink.remove();
+
+    // confirm that the symlink disappeared but the original file is still present
+    QVERIFY(QFile::exists(temp.fileName()));
+    QVERIFY(!QFile::exists(linkName));
+    cleanLink.dismiss();
+}
+
+void tst_QFile::moveToTrashSymlinkToDirectory_data()
+{
+    QTest::addColumn<bool>("appendSlash");
+    QTest::newRow("without-slash") << false;
+    QTest::newRow("with-slash") << true;
+}
+
+void tst_QFile::moveToTrashSymlinkToDirectory()
+{
+#if defined(Q_OS_ANDROID) || defined(Q_OS_WEBOS) || defined(Q_OS_VXWORKS)
+    QSKIP("This platform doesn't implement a trash bin");
+#endif
+    QFETCH(bool, appendSlash);
+    QTemporaryDir temp(QDir::homePath() + "/tst_qfile.moveToTrashSymlinkDir.XXXXXX");
+    QVERIFY2(temp.isValid(), "Failed to create temporary dir: " + temp.errorString().toLocal8Bit());
+
+    // Create the symlink
+    const QString linkName = temp.path() + ".lnk";
+    QVERIFY(QFile::link(temp.path(), linkName));
+    auto cleanLink = qScopeGuard([&]() {
+        QFile::remove(linkName);
+    });
+
+    // now trash it
+    QFile symlink(appendSlash ? linkName + u'/' : linkName);
+    QVERIFY(symlink.moveToTrash());
+    QCOMPARE_NE(symlink.fileName(), linkName);
+    QCOMPARE_NE(symlink.fileName(), linkName + u'/');
+
+    // confirm that the target is still a symlink
+    QFileInfo fi(symlink.fileName());
+    QVERIFY(fi.isSymLink());
+    QVERIFY(fi.isDir());    // we used an absolute path, so it should not be broken!
+    symlink.remove();
+
+    // confirm that the symlink disappeared but the original dir is still present
+    QVERIFY(QFile::exists(temp.path()));
+    QVERIFY(!QFile::exists(linkName));
+    cleanLink.dismiss();
+}
+
 void tst_QFile::moveToTrashXdgSafety()
 {
 #if defined(Q_OS_VXWORKS)