diff --git a/libs/image/kis_image_config.cpp b/libs/image/kis_image_config.cpp
index e87039cbeb..ab4550d59e 100644
--- a/libs/image/kis_image_config.cpp
+++ b/libs/image/kis_image_config.cpp
@@ -1,609 +1,635 @@
 /*
  *  Copyright (c) 2010 Dmitry Kazakov <dimula73@gmail.com>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
 #include "kis_image_config.h"
 
 #include <ksharedconfig.h>
 
 #include <KoConfig.h>
 #include <KoColorProfile.h>
 #include <KoColorSpaceRegistry.h>
 #include <KoColorConversionTransformation.h>
 
 #include "kis_debug.h"
 
 #include <QThread>
 #include <QApplication>
 #include <QColor>
 #include <QDir>
 
 #include "kis_global.h"
 #include <cmath>
+#include <QTemporaryFile>
 
 #ifdef Q_OS_MACOS
 #include <errno.h>
 #endif
 
 KisImageConfig::KisImageConfig(bool readOnly)
     : m_config(KSharedConfig::openConfig()->group(QString()))
     , m_readOnly(readOnly)
 {
     if (!readOnly) {
         KIS_SAFE_ASSERT_RECOVER_RETURN(qApp->thread() == QThread::currentThread());
     }
 #ifdef Q_OS_MACOS
     // clear /var/folders/ swap path set by old broken Krita swap implementation in order to use new default swap dir.
     QString swap = m_config.readEntry("swaplocation", "");
     if (swap.startsWith("/var/folders/")) {
         m_config.deleteEntry("swaplocation");
     }
 #endif
 }
 
 KisImageConfig::~KisImageConfig()
 {
     if (m_readOnly) return;
 
     if (qApp->thread() != QThread::currentThread()) {
         dbgKrita << "KisImageConfig: requested config synchronization from nonGUI thread! Called from" << kisBacktrace();
         return;
     }
 
     m_config.sync();
 }
 
 bool KisImageConfig::enableProgressReporting(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("enableProgressReporting", true) : true;
 }
 
 void KisImageConfig::setEnableProgressReporting(bool value)
 {
     m_config.writeEntry("enableProgressReporting", value);
 }
 
 bool KisImageConfig::enablePerfLog(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("enablePerfLog", false) :false;
 }
 
 void KisImageConfig::setEnablePerfLog(bool value)
 {
     m_config.writeEntry("enablePerfLog", value);
 }
 
 qreal KisImageConfig::transformMaskOffBoundsReadArea() const
 {
     return m_config.readEntry("transformMaskOffBoundsReadArea", 0.5);
 }
 
 int KisImageConfig::updatePatchHeight() const
 {
     return m_config.readEntry("updatePatchHeight", 512);
 }
 
 void KisImageConfig::setUpdatePatchHeight(int value)
 {
     m_config.writeEntry("updatePatchHeight", value);
 }
 
 int KisImageConfig::updatePatchWidth() const
 {
     return m_config.readEntry("updatePatchWidth", 512);
 }
 
 void KisImageConfig::setUpdatePatchWidth(int value)
 {
     m_config.writeEntry("updatePatchWidth", value);
 }
 
 qreal KisImageConfig::maxCollectAlpha() const
 {
     return m_config.readEntry("maxCollectAlpha", 2.5);
 }
 
 qreal KisImageConfig::maxMergeAlpha() const
 {
     return m_config.readEntry("maxMergeAlpha", 1.);
 }
 
 qreal KisImageConfig::maxMergeCollectAlpha() const
 {
     return m_config.readEntry("maxMergeCollectAlpha", 1.5);
 }
 
 qreal KisImageConfig::schedulerBalancingRatio() const
 {
     /**
      * updates-queue-size / strokes-queue-size
      */
     return m_config.readEntry("schedulerBalancingRatio", 100.);
 }
 
 void KisImageConfig::setSchedulerBalancingRatio(qreal value)
 {
     m_config.writeEntry("schedulerBalancingRatio", value);
 }
 
 int KisImageConfig::maxSwapSize(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("maxSwapSize", 4096) : 4096; // in MiB
 }
 
 void KisImageConfig::setMaxSwapSize(int value)
 {
     m_config.writeEntry("maxSwapSize", value);
 }
 
 int KisImageConfig::swapSlabSize() const
 {
     return m_config.readEntry("swapSlabSize", 64); // in MiB
 }
 
 void KisImageConfig::setSwapSlabSize(int value)
 {
     m_config.writeEntry("swapSlabSize", value);
 }
 
 int KisImageConfig::swapWindowSize() const
 {
     return m_config.readEntry("swapWindowSize", 16); // in MiB
 }
 
 void KisImageConfig::setSwapWindowSize(int value)
 {
     m_config.writeEntry("swapWindowSize", value);
 }
 
 int KisImageConfig::tilesHardLimit() const
 {
     qreal hp = qreal(memoryHardLimitPercent()) / 100.0;
     qreal pp = qreal(memoryPoolLimitPercent()) / 100.0;
 
     return totalRAM() * hp * (1 - pp);
 }
 
 int KisImageConfig::tilesSoftLimit() const
 {
     qreal sp = qreal(memorySoftLimitPercent()) / 100.0;
 
     return tilesHardLimit() * sp;
 }
 
 int KisImageConfig::poolLimit() const
 {
     qreal hp = qreal(memoryHardLimitPercent()) / 100.0;
     qreal pp = qreal(memoryPoolLimitPercent()) / 100.0;
 
     return totalRAM() * hp * pp;
 }
 
 qreal KisImageConfig::memoryHardLimitPercent(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("memoryHardLimitPercent", 50.) : 50.;
 }
 
 void KisImageConfig::setMemoryHardLimitPercent(qreal value)
 {
     m_config.writeEntry("memoryHardLimitPercent", value);
 }
 
 qreal KisImageConfig::memorySoftLimitPercent(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("memorySoftLimitPercent", 2.) : 2.;
 }
 
 void KisImageConfig::setMemorySoftLimitPercent(qreal value)
 {
     m_config.writeEntry("memorySoftLimitPercent", value);
 }
 
 qreal KisImageConfig::memoryPoolLimitPercent(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("memoryPoolLimitPercent", 0.0) : 0.0;
 }
 
 void KisImageConfig::setMemoryPoolLimitPercent(qreal value)
 {
     m_config.writeEntry("memoryPoolLimitPercent", value);
 }
 
 QString KisImageConfig::safelyGetWritableTempLocation(const QString &suffix, const QString &configKey, bool requestDefault) const
 {
 #ifdef Q_OS_MACOS
     // On OSX, QDir::tempPath() gives us a folder we cannot reply upon (usually
     // something like /var/folders/.../...) and that will have vanished when we
     // try to create the tmp file in KisMemoryWindow::KisMemoryWindow using
     // swapFileTemplate. thus, we just pick the home folder if swapDir does not
     // tell us otherwise.
 
     // the other option here would be to use a "garbled name" temp file (i.e. no name
     // KRITA_SWAP_FILE_XXXXXX) in an obscure /var/folders place, which is not
     // nice to the user. having a clearly named swap file in the home folder is
     // much nicer to Krita's users.
 
     // furthermore, this is just a default and swapDir can always be configured
     // to another location.
 
     QString swap = QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation) + QDir::separator() + suffix;
 #else
     Q_UNUSED(suffix);
     QString swap = QDir::tempPath();
 #endif
     if (requestDefault) {
        return swap;
     }
     const QString configuredSwap = m_config.readEntry(configKey, swap);
     if (!configuredSwap.isEmpty()) {
         swap = configuredSwap;
     }
 
-    // Gosh, everything fails, nothing is writable, swap to the homedir
-    if (!QFileInfo(swap).isWritable()) {
-        swap = QDir::homePath();
-        Q_ASSERT(QFileInfo(swap).isWritable());
+    QString chosenLocation;
+    QStringList proposedSwapLocations;
+    proposedSwapLocations << swap;
+    proposedSwapLocations << QDir::tempPath();
+    proposedSwapLocations << QDir::homePath();
+
+    Q_FOREACH (const QString location, proposedSwapLocations) {
+        if (!QFileInfo(location).isWritable()) continue;
+
+        /**
+         * On NTFS, isWritable() doesn't check for attributes due to performance
+         * reasons, so we should try it in a brute-force way...
+         * (yes, there is a hacky-global-variable workaround, but let's be safe)
+         */
+        QTemporaryFile tempFile;
+        tempFile.setFileTemplate(location + QDir::separator() + "krita_test_swap_location");
+        if (tempFile.open() && !tempFile.fileName().isEmpty()) {
+            chosenLocation = location;
+            break;
+        }
     }
 
+    if (chosenLocation.isEmpty()) {
+        qCritical() << "CRITICAL: no writable location for a swap file found! Tried the following paths:" << proposedSwapLocations;
+        qCritical() << "CRITICAL: hope I don't crash...";
+        chosenLocation = swap;
+    }
+
+    if (chosenLocation != swap) {
+        qWarning() << "WARNING: configured swap location is not writable, using a fall-back location" << swap << "->" << chosenLocation;
+    }
 
-    return swap;
+    return chosenLocation;
 }
 
 
 QString KisImageConfig::swapDir(bool requestDefault)
 {
     return safelyGetWritableTempLocation("swap", "swaplocation", requestDefault);
 }
 
 void KisImageConfig::setSwapDir(const QString &swapDir)
 {
     m_config.writeEntry("swaplocation", swapDir);
 }
 
 int KisImageConfig::numberOfOnionSkins() const
 {
     return m_config.readEntry("numberOfOnionSkins", 10);
 }
 
 void KisImageConfig::setNumberOfOnionSkins(int value)
 {
     m_config.writeEntry("numberOfOnionSkins", value);
 }
 
 int KisImageConfig::onionSkinTintFactor() const
 {
     return m_config.readEntry("onionSkinTintFactor", 192);
 }
 
 void KisImageConfig::setOnionSkinTintFactor(int value)
 {
     m_config.writeEntry("onionSkinTintFactor", value);
 }
 
 int KisImageConfig::onionSkinOpacity(int offset) const
 {
     int value = m_config.readEntry("onionSkinOpacity_" + QString::number(offset), -1);
 
     if (value < 0) {
         const int num = numberOfOnionSkins();
         const qreal dx = qreal(qAbs(offset)) / num;
         value = 0.7 * exp(-pow2(dx) / 0.5) * 255;
     }
 
     return value;
 }
 
 void KisImageConfig::setOnionSkinOpacity(int offset, int value)
 {
     m_config.writeEntry("onionSkinOpacity_" + QString::number(offset), value);
 }
 
 bool KisImageConfig::onionSkinState(int offset) const
 {
     bool enableByDefault = (qAbs(offset) <= 2);
     return m_config.readEntry("onionSkinState_" + QString::number(offset), enableByDefault);
 }
 
 void KisImageConfig::setOnionSkinState(int offset, bool value)
 {
     m_config.writeEntry("onionSkinState_" + QString::number(offset), value);
 }
 
 QColor KisImageConfig::onionSkinTintColorBackward() const
 {
     return m_config.readEntry("onionSkinTintColorBackward", QColor(Qt::red));
 }
 
 void KisImageConfig::setOnionSkinTintColorBackward(const QColor &value)
 {
     m_config.writeEntry("onionSkinTintColorBackward", value);
 }
 
 QColor KisImageConfig::onionSkinTintColorForward() const
 {
     return m_config.readEntry("oninSkinTintColorForward", QColor(Qt::green));
 }
 
 void KisImageConfig::setOnionSkinTintColorForward(const QColor &value)
 {
     m_config.writeEntry("oninSkinTintColorForward", value);
 }
 
 bool KisImageConfig::lazyFrameCreationEnabled(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("lazyFrameCreationEnabled", true) : true;
 }
 
 void KisImageConfig::setLazyFrameCreationEnabled(bool value)
 {
     m_config.writeEntry("lazyFrameCreationEnabled", value);
 }
 
 
 #if defined Q_OS_LINUX
 #include <sys/sysinfo.h>
 #elif defined Q_OS_FREEBSD || defined Q_OS_NETBSD || defined Q_OS_OPENBSD
 #include <sys/sysctl.h>
 #elif defined Q_OS_WIN
 #include <windows.h>
 #elif defined Q_OS_MACOS
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #endif
 
 int KisImageConfig::totalRAM()
 {
     // let's think that default memory size is 1000MiB
     int totalMemory = 1000; // MiB
     int error = 1;
 
 #if defined Q_OS_LINUX
     struct sysinfo info;
 
     error = sysinfo(&info);
     if(!error) {
         totalMemory = info.totalram * info.mem_unit / (1UL << 20);
     }
 #elif defined Q_OS_FREEBSD || defined Q_OS_NETBSD || defined Q_OS_OPENBSD
     u_long physmem;
 #   if defined HW_PHYSMEM64 // NetBSD only
     int mib[] = {CTL_HW, HW_PHYSMEM64};
 #   else
     int mib[] = {CTL_HW, HW_PHYSMEM};
 #   endif
     size_t len = sizeof(physmem);
 
     error = sysctl(mib, 2, &physmem, &len, 0, 0);
     if(!error) {
         totalMemory = physmem >> 20;
     }
 #elif defined Q_OS_WIN
     MEMORYSTATUSEX status;
     status.dwLength = sizeof(status);
     error  = !GlobalMemoryStatusEx(&status);
 
     if (!error) {
         totalMemory = status.ullTotalPhys >> 20;
     }
 
     // For 32 bit windows, the total memory available is at max the 2GB per process memory limit.
 #   if defined ENV32BIT
     totalMemory = qMin(totalMemory, 2000);
 #   endif
 #elif defined Q_OS_MACOS
     int mib[2] = { CTL_HW, HW_MEMSIZE };
     u_int namelen = sizeof(mib) / sizeof(mib[0]);
     uint64_t size;
     size_t len = sizeof(size);
 
     errno = 0;
     if (sysctl(mib, namelen, &size, &len, 0, 0) >= 0) {
         totalMemory = size >> 20;
         error = 0;
     }
     else {
         dbgKrita << "sysctl(\"hw.memsize\") raised error" << strerror(errno);
     }
 #endif
 
     if (error) {
         warnKrita << "Cannot get the size of your RAM. Using 1 GiB by default.";
     }
 
     return totalMemory;
 }
 
 bool KisImageConfig::showAdditionalOnionSkinsSettings(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("showAdditionalOnionSkinsSettings", true) : true;
 }
 
 void KisImageConfig::setShowAdditionalOnionSkinsSettings(bool value)
 {
     m_config.writeEntry("showAdditionalOnionSkinsSettings", value);
 }
 
 int KisImageConfig::defaultFrameColorLabel() const
 {
     return m_config.readEntry("defaultFrameColorLabel", 0);
 }
 
 void KisImageConfig::setDefaultFrameColorLabel(int label)
 {
     m_config.writeEntry("defaultFrameColorLabel", label);
 }
 
 KisProofingConfigurationSP KisImageConfig::defaultProofingconfiguration()
 {
     KisProofingConfiguration *proofingConfig= new KisProofingConfiguration();
     proofingConfig->proofingProfile = m_config.readEntry("defaultProofingProfileName", "Chemical proof");
     proofingConfig->proofingModel = m_config.readEntry("defaultProofingProfileModel", "CMYKA");
     proofingConfig->proofingDepth = m_config.readEntry("defaultProofingProfileDepth", "U8");
     proofingConfig->intent = (KoColorConversionTransformation::Intent)m_config.readEntry("defaultProofingProfileIntent", 3);
     if (m_config.readEntry("defaultProofingBlackpointCompensation", true)) {
         proofingConfig->conversionFlags  |= KoColorConversionTransformation::ConversionFlag::BlackpointCompensation;
     } else {
         proofingConfig->conversionFlags  = proofingConfig->conversionFlags & ~KoColorConversionTransformation::ConversionFlag::BlackpointCompensation;
     }
     QColor def(Qt::green);
     m_config.readEntry("defaultProofingGamutwarning", def);
     KoColor col(KoColorSpaceRegistry::instance()->rgb8());
     col.fromQColor(def);
     col.setOpacity(1.0);
     proofingConfig->warningColor = col;
     proofingConfig->adaptationState = (double)m_config.readEntry("defaultProofingAdaptationState", 1.0);
     return toQShared(proofingConfig);
 }
 
 void KisImageConfig::setDefaultProofingConfig(const KoColorSpace *proofingSpace, int proofingIntent, bool blackPointCompensation, KoColor warningColor, double adaptationState)
 {
     m_config.writeEntry("defaultProofingProfileName", proofingSpace->profile()->name());
     m_config.writeEntry("defaultProofingProfileModel", proofingSpace->colorModelId().id());
     m_config.writeEntry("defaultProofingProfileDepth", proofingSpace->colorDepthId().id());
     m_config.writeEntry("defaultProofingProfileIntent", proofingIntent);
     m_config.writeEntry("defaultProofingBlackpointCompensation", blackPointCompensation);
     QColor c;
     c = warningColor.toQColor();
     m_config.writeEntry("defaultProofingGamutwarning", c);
     m_config.writeEntry("defaultProofingAdaptationState",adaptationState);
 }
 
 bool KisImageConfig::useLodForColorizeMask(bool requestDefault) const
 {
     return !requestDefault ?
         m_config.readEntry("useLodForColorizeMask", false) : false;
 }
 
 void KisImageConfig::setUseLodForColorizeMask(bool value)
 {
     m_config.writeEntry("useLodForColorizeMask", value);
 }
 
 int KisImageConfig::maxNumberOfThreads(bool defaultValue) const
 {
     return (defaultValue ? QThread::idealThreadCount() : m_config.readEntry("maxNumberOfThreads", QThread::idealThreadCount()));
 }
 
 void KisImageConfig::setMaxNumberOfThreads(int value)
 {
     if (value == QThread::idealThreadCount()) {
         m_config.deleteEntry("maxNumberOfThreads");
     } else {
         m_config.writeEntry("maxNumberOfThreads", value);
     }
 }
 
 int KisImageConfig::frameRenderingClones(bool defaultValue) const
 {
     const int defaultClonesCount = qMax(1, maxNumberOfThreads(defaultValue) / 2);
     return defaultValue ? defaultClonesCount : m_config.readEntry("frameRenderingClones", defaultClonesCount);
 }
 
 void KisImageConfig::setFrameRenderingClones(int value)
 {
     m_config.writeEntry("frameRenderingClones", value);
 }
 
 int KisImageConfig::fpsLimit(bool defaultValue) const
 {
     int limit = defaultValue ? 100 : m_config.readEntry("fpsLimit", 100);
     return limit > 0 ? limit : 1;
 }
 
 void KisImageConfig::setFpsLimit(int value)
 {
     m_config.writeEntry("fpsLimit", value);
 }
 
 bool KisImageConfig::useOnDiskAnimationCacheSwapping(bool defaultValue) const
 {
     return defaultValue ? true : m_config.readEntry("useOnDiskAnimationCacheSwapping", true);
 }
 
 void KisImageConfig::setUseOnDiskAnimationCacheSwapping(bool value)
 {
     m_config.writeEntry("useOnDiskAnimationCacheSwapping", value);
 }
 
 QString KisImageConfig::animationCacheDir(bool defaultValue) const
 {
     return safelyGetWritableTempLocation("animation_cache", "animationCacheDir", defaultValue);
 }
 
 void KisImageConfig::setAnimationCacheDir(const QString &value)
 {
     m_config.writeEntry("animationCacheDir", value);
 }
 
 bool KisImageConfig::useAnimationCacheFrameSizeLimit(bool defaultValue) const
 {
     return defaultValue ? true : m_config.readEntry("useAnimationCacheFrameSizeLimit", true);
 }
 
 void KisImageConfig::setUseAnimationCacheFrameSizeLimit(bool value)
 {
     m_config.writeEntry("useAnimationCacheFrameSizeLimit", value);
 }
 
 int KisImageConfig::animationCacheFrameSizeLimit(bool defaultValue) const
 {
     return defaultValue ? 2500 : m_config.readEntry("animationCacheFrameSizeLimit", 2500);
 }
 
 void KisImageConfig::setAnimationCacheFrameSizeLimit(int value)
 {
     m_config.writeEntry("animationCacheFrameSizeLimit", value);
 }
 
 bool KisImageConfig::useAnimationCacheRegionOfInterest(bool defaultValue) const
 {
     return defaultValue ? true : m_config.readEntry("useAnimationCacheRegionOfInterest", true);
 }
 
 void KisImageConfig::setUseAnimationCacheRegionOfInterest(bool value)
 {
     m_config.writeEntry("useAnimationCacheRegionOfInterest", value);
 }
 
 qreal KisImageConfig::animationCacheRegionOfInterestMargin(bool defaultValue) const
 {
     return defaultValue ? 0.25 : m_config.readEntry("animationCacheRegionOfInterestMargin", 0.25);
 }
 
 void KisImageConfig::setAnimationCacheRegionOfInterestMargin(qreal value)
 {
     m_config.writeEntry("animationCacheRegionOfInterestMargin", value);
 }
 
 QColor KisImageConfig::selectionOverlayMaskColor(bool defaultValue) const
 {
     QColor def(255, 0, 0, 128);
     return (defaultValue ? def : m_config.readEntry("selectionOverlayMaskColor", def));
 }
 
 void KisImageConfig::setSelectionOverlayMaskColor(const QColor &color)
 {
     m_config.writeEntry("selectionOverlayMaskColor", color);
 }