Better detection of writeability of current app directory.

src/miscellaneous/iofactory.cpp

@@ -24,12 +24,25 @@
 #include <QFileInfo>
 #include <QFile>
 #include <QObject>
+#include <QTemporaryFile>
 #include <QTextStream>
 
 
 IOFactory::IOFactory() {
 }
 
+bool IOFactory::isFolderWritable(const QString &folder) {
+  QString real_file = folder;
+
+  if (!real_file.endsWith(QDir::separator())) {
+    real_file += QDir::separator();
+  }
+
+  real_file += "test-permissions-file";
+
+  return QTemporaryFile(real_file).open();
+}
+
 QString IOFactory::getSystemFolder(QStandardPaths::StandardLocation location) {
   return QStandardPaths::writableLocation(location);
 }

src/miscellaneous/iofactory.h

@@ -31,7 +31,9 @@ class IOFactory {
   private:
     IOFactory();
 
-  public:   
+  public:
+    static bool isFolderWritable(const QString &folder);
+
     // Returns system-wide folder according to type.
     static QString getSystemFolder(QStandardPaths::StandardLocation location);
 

src/miscellaneous/settings.cpp

@@ -332,7 +332,7 @@ SettingsProperties Settings::determineProperties() {
   const QString home_path = qApp->homeFolderPath() + QDir::separator() + QString(APP_LOW_H_NAME);
   const QString home_path_file = home_path + properties.m_settingsSuffix;
 
-  const bool portable_settings_available = QFileInfo(app_path).isWritable();
+  const bool portable_settings_available = IOFactory::isFolderWritable(app_path);
   const bool non_portable_settings_exist = QFile::exists(home_path_file);
 
   // We will use PORTABLE settings only and only if it is available and NON-PORTABLE