QFile::rename: use the open file's ID, instead of using the file name

To do that, we needed to add virtual id() in QAbstractFileEngine and
override it in QFSFileEngine. It might be useful to return other types
of IDs for the other file engines, but this commit does not attempt that
just yet.

Change-Id: I1eba2b016de74620bfc8fffd14ccafe0762b3c38
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/corelib/io/qfsfileengine_win.cpp b/src/corelib/io/qfsfileengine_win.cpp
index fb3cdd3981..7a010df671 100644
--- a/src/corelib/io/qfsfileengine_win.cpp
+++ b/src/corelib/io/qfsfileengine_win.cpp
@@ -718,6 +718,24 @@ QAbstractFileEngine::FileFlags QFSFileEngine::fileFlags(QAbstractFileEngine::Fil
     return ret;
 }
 
+QByteArray QFSFileEngine::id() const
+{
+    Q_D(const QFSFileEngine);
+    HANDLE h = d->fileHandle;
+    if (h == INVALID_HANDLE_VALUE) {
+        int localFd = d->fd;
+        if (d->fh && d->fileEntry.isEmpty())
+            localFd = QT_FILENO(d->fh);
+        if (localFd != -1)
+            h = HANDLE(_get_osfhandle(localFd));
+    }
+    if (h != INVALID_HANDLE_VALUE)
+        return QFileSystemEngine::id(h);
+
+    // file is not open, try by path
+    return QFileSystemEngine::id(d->fileEntry);
+}
+
 QString QFSFileEngine::fileName(FileName file) const
 {
     Q_D(const QFSFileEngine);