Made safe writing of files optional

Since the safe (atomic) writing of files is unfortunately causing
problems on network drives and in Dropbox folders, there is now an
option to disable it entirely.

Users should be aware that disabling it will result in partially written
files in the event of Tiled crashing while saving or when there is
insufficient space available. When overwriting, the previous contents of
the file will become unavailable, so backups should be made.

Closes #1402
Closes #1404

src/libtiled/libtiled.pro

@@ -46,6 +46,7 @@ SOURCES += compression.cpp \
     plugin.cpp \
     pluginmanager.cpp \
     properties.cpp \
+    savefile.cpp \
     staggeredrenderer.cpp \
     tile.cpp \
     tileanimationdriver.cpp \
@@ -76,6 +77,7 @@ HEADERS += compression.h \
     plugin.h \
     pluginmanager.h \
     properties.h \
+    savefile.h \
     staggeredrenderer.h \
     terrain.h \
     tile.h \

src/libtiled/libtiled.qbs

@@ -75,6 +75,8 @@ DynamicLibrary {
         "pluginmanager.h",
         "properties.cpp",
         "properties.h",
+        "savefile.cpp",
+        "savefile.h",
         "staggeredrenderer.cpp",
         "staggeredrenderer.h",
         "tile.cpp",

src/libtiled/mapwriter.cpp

@@ -36,6 +36,7 @@
 #include "mapobject.h"
 #include "imagelayer.h"
 #include "objectgroup.h"
+#include "savefile.h"
 #include "tile.h"
 #include "tilelayer.h"
 #include "tileset.h"
@@ -44,7 +45,6 @@
 #include <QBuffer>
 #include <QCoreApplication>
 #include <QDir>
-#include <QSaveFile>
 #include <QXmlStreamWriter>
 
 using namespace Tiled;
@@ -73,7 +73,7 @@ class MapWriterPrivate
     void writeTileset(const Tileset &tileset, QIODevice *device,
                       const QString &path);
 
-    bool openFile(QIODevice *file);
+    bool openFile(SaveFile *file);
 
     QString mError;
     Map::LayerDataFormat mLayerDataFormat;
@@ -107,7 +107,7 @@ MapWriterPrivate::MapWriterPrivate()
 {
 }
 
-bool MapWriterPrivate::openFile(QIODevice *file)
+bool MapWriterPrivate::openFile(SaveFile *file)
 {
     if (!file->open(QIODevice::WriteOnly | QIODevice::Text)) {
         mError = tr("Could not open file for writing.");
@@ -677,13 +677,13 @@ void MapWriter::writeMap(const Map *map, QIODevice *device,
 
 bool MapWriter::writeMap(const Map *map, const QString &fileName)
 {
-    QSaveFile file(fileName);
+    SaveFile file(fileName);
     if (!d->openFile(&file))
         return false;
 
-    writeMap(map, &file, QFileInfo(fileName).absolutePath());
+    writeMap(map, file.device(), QFileInfo(fileName).absolutePath());
 
-    if (file.error() != QFile::NoError) {
+    if (file.error() != QFileDevice::NoError) {
         d->mError = file.errorString();
         return false;
     }
@@ -704,13 +704,18 @@ void MapWriter::writeTileset(const Tileset &tileset, QIODevice *device,
 
 bool MapWriter::writeTileset(const Tileset &tileset, const QString &fileName)
 {
-    QFile file(fileName);
+    SaveFile file(fileName);
     if (!d->openFile(&file))
         return false;
 
-    writeTileset(tileset, &file, QFileInfo(fileName).absolutePath());
+    writeTileset(tileset, file.device(), QFileInfo(fileName).absolutePath());
 
-    if (file.error() != QFile::NoError) {
+    if (file.error() != QFileDevice::NoError) {
+        d->mError = file.errorString();
+        return false;
+    }
+
+    if (!file.commit()) {
         d->mError = file.errorString();
         return false;
     }

src/libtiled/savefile.cpp

@@ -0,0 +1,64 @@
+/*
+ * savefile.cpp
+ * Copyright 2017, Thorbjørn Lindeijer <bjorn@lindeijer.nl>
+ *
+ * This file is part of libtiled.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice,
+ *       this list of conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "savefile.h"
+
+#include <QFile>
+#include <QSaveFile>
+
+namespace Tiled {
+
+bool SaveFile::mSafeSavingEnabled = true;
+
+SaveFile::SaveFile(const QString &name)
+{
+    if (mSafeSavingEnabled)
+        mFileDevice.reset(new QSaveFile(name));
+    else
+        mFileDevice.reset(new QFile(name));
+}
+
+bool SaveFile::commit()
+{
+    if (auto saveFile = qobject_cast<QSaveFile*>(mFileDevice.data()))
+        return saveFile->commit();
+
+    return mFileDevice->error() == QFileDevice::NoError;
+}
+
+bool SaveFile::safeSavingEnabled()
+{
+    return mSafeSavingEnabled;
+}
+
+void SaveFile::setSafeSavingEnabled(bool enabled)
+{
+    mSafeSavingEnabled = enabled;
+}
+
+} // namespace Tiled

src/libtiled/savefile.h

@@ -0,0 +1,89 @@
+/*
+ * savefile.h
+ * Copyright 2017, Thorbjørn Lindeijer <bjorn@lindeijer.nl>
+ *
+ * This file is part of libtiled.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice,
+ *       this list of conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef SAVEFILE_H
+#define SAVEFILE_H
+
+#include "tiled_global.h"
+
+#include <QFileDevice>
+#include <QScopedPointer>
+#include <QString>
+
+namespace Tiled {
+
+/**
+ * A wrapper around QSaveFile and QFile. Allows safe writing of files to be
+ * turned off globally.
+ */
+class TILEDSHARED_EXPORT SaveFile
+{
+public:
+    SaveFile(const QString &name);
+
+    QFileDevice* device() const;
+
+    bool open(QIODevice::OpenMode mode);
+    bool commit();
+
+    QFileDevice::FileError error() const;
+    QString errorString() const;
+
+    static bool safeSavingEnabled();
+    static void setSafeSavingEnabled(bool enabled);
+
+private:
+    QScopedPointer<QFileDevice> mFileDevice;
+
+    static bool mSafeSavingEnabled;
+};
+
+
+inline QFileDevice *SaveFile::device() const
+{
+    return mFileDevice.data();
+}
+
+inline bool SaveFile::open(QIODevice::OpenMode mode)
+{
+    return mFileDevice->open(mode);
+}
+
+inline QFileDevice::FileError SaveFile::error() const
+{
+    return mFileDevice->error();
+}
+
+inline QString SaveFile::errorString() const
+{
+    return mFileDevice->errorString();
+}
+
+} // namespace Tiled
+
+#endif // SAVEFILE_H

src/plugins/csv/csvplugin.cpp

@@ -21,13 +21,12 @@
 #include "csvplugin.h"
 
 #include "map.h"
+#include "savefile.h"
 #include "tile.h"
 #include "tilelayer.h"
 
 #include <QDir>
-#include <QFile>
 #include <QFileInfo>
-#include <QSaveFile>
 
 using namespace Tiled;
 using namespace Csv;
@@ -43,39 +42,41 @@ bool CsvPlugin::write(const Map *map, const QString &fileName)
 
     // Traverse all tile layers
     uint currentLayer = 0u;
-    foreach (const Layer *layer, map->layers()) {
+    for (const Layer *layer : map->layers()) {
         if (layer->layerType() != Layer::TileLayerType)
             continue;
 
         const TileLayer *tileLayer = static_cast<const TileLayer*>(layer);
 
-        QSaveFile file(layerPaths.at(currentLayer));
+        SaveFile file(layerPaths.at(currentLayer));
 
         if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
             mError = tr("Could not open file for writing.");
             return false;
         }
 
+        auto device = file.device();
+
         // Write out tiles either by ID or their name, if given. -1 is "empty"
         for (int y = 0; y < tileLayer->height(); ++y) {
             for (int x = 0; x < tileLayer->width(); ++x) {
                 if (x > 0)
-                    file.write(",", 1);
+                    device->write(",", 1);
 
                 const Cell &cell = tileLayer->cellAt(x, y);
                 const Tile *tile = cell.tile();
                 if (tile && tile->hasProperty(QLatin1String("name"))) {
-                    file.write(tile->property(QLatin1String("name")).toString().toUtf8());
+                    device->write(tile->property(QLatin1String("name")).toString().toUtf8());
                 } else {
                     const int id = tile ? tile->id() : -1;
-                    file.write(QByteArray::number(id));
+                    device->write(QByteArray::number(id));
                 }
             }
 
-            file.write("\n", 1);
+            device->write("\n", 1);
         }
 
-        if (file.error() != QFile::NoError) {
+        if (file.error() != QFileDevice::NoError) {
             mError = file.errorString();
             return false;
         }
@@ -105,7 +106,7 @@ QStringList CsvPlugin::outputFiles(const Tiled::Map *map, const QString &fileNam
     const QString path = fileInfo.path();
 
     // Loop layers to calculate the path for the exported file
-    foreach (const Layer *layer, map->layers()) {
+    for (const Layer *layer : map->layers()) {
         if (layer->layerType() != Layer::TileLayerType)
             continue;
 

src/plugins/defold/defoldplugin.cpp

@@ -23,16 +23,16 @@
 
 #include "tokendefines.h"
 
-#include <QSaveFile>
-#include <QTextStream>
-
 #include "layer.h"
 #include "map.h"
 #include "mapobject.h"
 #include "objectgroup.h"
+#include "savefile.h"
 #include "tile.h"
 #include "tilelayer.h"
 
+#include <QTextStream>
+
 #include <cmath>
 
 namespace Defold {
@@ -119,15 +119,15 @@ bool DefoldPlugin::write(const Tiled::Map *map, const QString &fileName)
     map_h["tile_set"] = "";
 
     QString result = replaceTags(QLatin1String(map_t), map_h);
-    QSaveFile mapFile(fileName);
+    Tiled::SaveFile mapFile(fileName);
     if (!mapFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
         mError = tr("Could not open file for writing.");
         return false;
     }
-    QTextStream stream(&mapFile);
+    QTextStream stream(mapFile.device());
     stream << result;
 
-    if (mapFile.error() != QSaveFile::NoError) {
+    if (mapFile.error() != QFileDevice::NoError) {
         mError = mapFile.errorString();
         return false;
     }