Check the correct path for .sync_*.db and ._sync_*.db

The dir() method will return the *parent* directory of the
file/directory in the QFileInfo. So if "~/ownCloud" was passed in as the
path, the check for .sync_*.db would be done on "~/".

Because we're migrating from ._sync_*.db to .sync_*.db, it will now also
check for the old filename.

Fixes: #8849

Author: erikjv

src/gui/folderman.cpp

@@ -1329,7 +1329,7 @@ static QString checkPathValidityRecursive(const QString &path)
     Utility::NtfsPermissionLookupRAII ntfs_perm;
 #endif
     const QFileInfo selFile(path);
-    if (!selFile.dir().entryList({ QStringLiteral(".sync_*.db") }, QDir::Hidden | QDir::Files).isEmpty()) {
+    if (!QDir(path).entryList({ QStringLiteral(".sync_*.db"), QStringLiteral("._sync_*.db") }, QDir::Hidden | QDir::Files).isEmpty()) {
         return FolderMan::tr("The folder %1 is used in a folder sync connection!").arg(QDir::toNativeSeparators(selFile.filePath()));
     }
 

test/testfolderman.cpp

@@ -128,6 +128,26 @@ private slots:
         QDir(dirPath + "/ownCloud2/").removeRecursively();
         QVERIFY(!folderman->checkPathValidityForNewFolder(dirPath + "/ownCloud2/blublu").isNull());
         QVERIFY(!folderman->checkPathValidityForNewFolder(dirPath + "/ownCloud2/sub/subsub/sub").isNull());
+
+        { // check for rejection of a directory with `.sync_*.db`
+            QVERIFY(dir2.mkpath("db-check1"));
+            QVERIFY(folderman->checkPathValidityForNewFolder(dirPath + "/db-check1").isNull());
+            QFile f(dirPath + "/db-check1/.sync_something.db");
+            QVERIFY(f.open(QFile::Truncate | QFile::WriteOnly));
+            f.close();
+            QVERIFY(QFileInfo::exists(dirPath + "/db-check1/.sync_something.db"));
+            QVERIFY(!folderman->checkPathValidityForNewFolder(dirPath + "/db-check1").isNull());
+        }
+
+        { // check for rejection of a directory with `._sync_*.db`
+            QVERIFY(dir2.mkpath("db-check2"));
+            QVERIFY(folderman->checkPathValidityForNewFolder(dirPath + "/db-check2").isNull());
+            QFile f(dirPath + "/db-check2/._sync_something.db");
+            QVERIFY(f.open(QFile::Truncate | QFile::WriteOnly));
+            f.close();
+            QVERIFY(QFileInfo::exists(dirPath + "/db-check2/._sync_something.db"));
+            QVERIFY(!folderman->checkPathValidityForNewFolder(dirPath + "/db-check2").isNull());
+        }
     }
 
     void testFindGoodPathForNewSyncFolder()