diff -urp -x '*.sw?' qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qfiledevice.cpp qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qfiledevice.cpp
--- qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qfiledevice.cpp	2018-09-13 07:25:10.000000000 +0300
+++ qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qfiledevice.cpp	2019-05-13 16:29:13.753430934 +0300
@@ -73,6 +73,37 @@ QAbstractFileEngine * QFileDevicePrivate
     return fileEngine;
 }
 
+bool QFileDevicePrivate::flush()
+{
+    if (!fileEngine) {
+        qWarning("QFileDevice::flush: No file engine. Is IODevice open?");
+        return false;
+    }
+
+    if (!writeBuffer.isEmpty()) {
+        qint64 size = writeBuffer.nextDataBlockSize();
+        qint64 written = fileEngine->write(writeBuffer.readPointer(), size);
+        if (written > 0)
+            writeBuffer.free(written);
+        if (written != size) {
+            QFileDevice::FileError err = fileEngine->error();
+            if (err == QFileDevice::UnspecifiedError)
+                err = QFileDevice::WriteError;
+            setError(err, fileEngine->errorString());
+            return false;
+        }
+    }
+
+    if (!fileEngine->flush()) {
+        QFileDevice::FileError err = fileEngine->error();
+        if (err == QFileDevice::UnspecifiedError)
+            err = QFileDevice::WriteError;
+        setError(err, fileEngine->errorString());
+        return false;
+    }
+    return true;
+}
+
 void QFileDevicePrivate::setError(QFileDevice::FileError err)
 {
     error = err;
@@ -282,33 +313,7 @@ QString QFileDevice::fileName() const
 bool QFileDevice::flush()
 {
     Q_D(QFileDevice);
-    if (!d->fileEngine) {
-        qWarning("QFileDevice::flush: No file engine. Is IODevice open?");
-        return false;
-    }
-
-    if (!d->writeBuffer.isEmpty()) {
-        qint64 size = d->writeBuffer.nextDataBlockSize();
-        qint64 written = d->fileEngine->write(d->writeBuffer.readPointer(), size);
-        if (written > 0)
-            d->writeBuffer.free(written);
-        if (written != size) {
-            QFileDevice::FileError err = d->fileEngine->error();
-            if (err == QFileDevice::UnspecifiedError)
-                err = QFileDevice::WriteError;
-            d->setError(err, d->fileEngine->errorString());
-            return false;
-        }
-    }
-
-    if (!d->fileEngine->flush()) {
-        QFileDevice::FileError err = d->fileEngine->error();
-        if (err == QFileDevice::UnspecifiedError)
-            err = QFileDevice::WriteError;
-        d->setError(err, d->fileEngine->errorString());
-        return false;
-    }
-    return true;
+    return d->flush();
 }
 
 /*!
diff -urp -x '*.sw?' qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qfiledevice_p.h qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qfiledevice_p.h
--- qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qfiledevice_p.h	2018-09-13 07:25:10.000000000 +0300
+++ qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qfiledevice_p.h	2019-05-13 16:25:22.064283884 +0300
@@ -69,6 +69,8 @@ protected:
 
     inline bool ensureFlushed() const;
 
+    virtual bool flush();
+
     bool putCharHelper(char c) override;
 
     void setError(QFileDevice::FileError err);
diff -urp -x '*.sw?' qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qsavefile.cpp qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qsavefile.cpp
--- qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qsavefile.cpp	2018-09-13 07:25:10.000000000 +0300
+++ qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qsavefile.cpp	2019-05-13 17:00:15.931840877 +0300
@@ -66,6 +66,18 @@ QSaveFilePrivate::~QSaveFilePrivate()
 {
 }
 
+bool QSaveFilePrivate::flush()
+{
+    if (writeError != QFileDevice::NoError)
+        return false;
+
+    const bool ret = QFileDevicePrivate::flush();
+
+    if (error != QFileDevice::NoError)
+        writeError = error;
+    return ret;
+}
+
 /*!
     \class QSaveFile
     \inmodule QtCore
diff -urp -x '*.sw?' qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qsavefile_p.h qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qsavefile_p.h
--- qt-everywhere-src-5.11.2.orig/qtbase/src/corelib/io/qsavefile_p.h	2018-09-13 07:25:10.000000000 +0300
+++ qt-everywhere-src-5.11.2/qtbase/src/corelib/io/qsavefile_p.h	2019-05-13 16:25:40.331264735 +0300
@@ -67,6 +67,8 @@ protected:
     QSaveFilePrivate();
     ~QSaveFilePrivate();
 
+    bool flush() override;
+
     QString fileName;
     QString finalFileName; // fileName with symbolic links resolved