Fix Document::saveAs with QSaveFile

QXlsx/header/xlsxzipwriter_p.h

@@ -6,6 +6,7 @@
 #include "xlsxglobal.h"
 
 #include <QIODevice>
+#include <QScopedPointer>
 #include <QString>
 
 class QZipWriter;
@@ -25,6 +26,7 @@ class ZipWriter
     void close();
 
 private:
+    QScopedPointer<QIODevice> m_deviceProxy;
     QZipWriter *m_writer;
 };
 

QXlsx/source/xlsxdocument.cpp

@@ -1365,7 +1365,8 @@ bool Document::saveAs(const QString &name) const
  * \overload
  * This function writes a document to the given \a device.
  *
- * \warning The \a device will be closed when this function returned.
+ * \warning The \a device will be closed when this function returns, except for
+ * QSaveFile. A QSaveFile remains open and must be committed by the caller.
  */
 bool Document::saveAs(QIODevice *device) const
 {

QXlsx/source/xlsxzipwriter.cpp

@@ -5,9 +5,55 @@
 #include <private/qzipwriter_p.h>
 
 #include <QDebug>
+#ifndef QT_NO_TEMPORARYFILE
+#include <QSaveFile>
+#endif
 
 QT_BEGIN_NAMESPACE_XLSX
 
+namespace {
+
+class NonClosingDevice : public QIODevice
+{
+public:
+    explicit NonClosingDevice(QIODevice *device)
+        : m_device(device)
+    {
+        if (device->isOpen())
+            QIODevice::open(device->openMode());
+    }
+
+    bool open(OpenMode mode) override
+    {
+        if (!m_device->isOpen() && !m_device->open(mode))
+            return false;
+        return QIODevice::open(m_device->openMode());
+    }
+
+    bool isSequential() const override { return m_device->isSequential(); }
+    qint64 pos() const override { return m_device->pos(); }
+    qint64 size() const override { return m_device->size(); }
+
+    bool seek(qint64 position) override
+    {
+        if (!m_device->seek(position))
+            return false;
+        return QIODevice::seek(position);
+    }
+
+protected:
+    qint64 readData(char *data, qint64 maxSize) override { return m_device->read(data, maxSize); }
+    qint64 writeData(const char *data, qint64 maxSize) override
+    {
+        return m_device->write(data, maxSize);
+    }
+
+private:
+    QIODevice *m_device;
+};
+
+} // namespace
+
 ZipWriter::ZipWriter(const QString &filePath)
 {
     m_writer = new QZipWriter(filePath, QIODevice::WriteOnly);
@@ -16,7 +62,11 @@ ZipWriter::ZipWriter(const QString &filePath)
 
 ZipWriter::ZipWriter(QIODevice *device)
 {
-    m_writer = new QZipWriter(device);
+#ifndef QT_NO_TEMPORARYFILE
+    if (qobject_cast<QSaveFile *>(device))
+        m_deviceProxy.reset(new NonClosingDevice(device));
+#endif
+    m_writer = new QZipWriter(m_deviceProxy ? m_deviceProxy.data() : device);
     m_writer->setCompressionPolicy(QZipWriter::AutoCompress);
 }