Image customization: search all mountpoints for config.txt

Search all mountpoints associated with the target drive for
FAT partition that has config.txt

Ref: #171

downloadthread.cpp

@@ -807,6 +807,7 @@ void DownloadThread::setImageCustomization(const QByteArray &config, const QByte
 bool DownloadThread::_customizeImage()
 {
     QString folder;
+    std::vector<std::string> mountpoints;
     QByteArray devlower = _filename.toLower();
 
     emit preparationStatusUpdate(tr("Waiting for FAT partition to be mounted"));
@@ -832,14 +833,14 @@ bool DownloadThread::_customizeImage()
         {
             if (QByteArray::fromStdString(i.device).toLower() == devlower && i.mountpoints.size())
             {
-                folder = QByteArray::fromStdString(i.mountpoints.front());
+                mountpoints = i.mountpoints;
                 break;
             }
         }
     }
 
 #ifdef Q_OS_WIN
-    if (folder.isEmpty() && !_nr.isEmpty()) {
+    if (mountpoints.empty() && !_nr.isEmpty()) {
         qDebug() << "Windows did not assign drive letter automatically. Ask diskpart to do so manually.";
         proc.start("diskpart");
         proc.waitForStarted();
@@ -855,7 +856,7 @@ bool DownloadThread::_customizeImage()
         {
             if (QByteArray::fromStdString(i.device).toLower() == devlower && i.mountpoints.size())
             {
-                folder = QByteArray::fromStdString(i.mountpoints.front());
+                mountpoints = i.mountpoints;
                 break;
             }
         }
@@ -865,7 +866,7 @@ bool DownloadThread::_customizeImage()
 #ifdef Q_OS_LINUX
     bool manualmount = false;
 
-    if (folder.isEmpty())
+    if (mountpoints.empty())
     {
         /* Manually mount folder */
         manualmount = true;
@@ -880,16 +881,16 @@ bool DownloadThread::_customizeImage()
             /* Not running as root, try to outsource mounting to udisks2 */
     #ifndef QT_NO_DBUS
             UDisks2Api udisks2;
-            folder = udisks2.mountDevice(fatpartition);
+            mountpoints.push_back(udisks2.mountDevice(fatpartition).toStdString());
     #endif
         }
         else
         {
             /* Running as root, attempt running mount directly */
             QTemporaryDir td;
             QStringList args;
-            folder = td.path();
-            args << "-t" << "vfat" << fatpartition << folder;
+            mountpoints.push_back(td.path().toStdString());
+            args << "-t" << "vfat" << fatpartition << td.path();
 
             if (QProcess::execute("mount", args) != 0)
             {
@@ -901,7 +902,7 @@ bool DownloadThread::_customizeImage()
     }
 #endif
 
-    if (folder.isEmpty())
+    if (mountpoints.empty())
     {
         //
         qDebug() << "drive info. searching for:" << devlower;
@@ -921,15 +922,32 @@ bool DownloadThread::_customizeImage()
 
     /* Some operating system take longer to complete mounting FAT32
        wait up to 3 seconds for config.txt file to appear */
-    QString configFilename = folder+"/config.txt";
+    QString configFilename;
+    bool foundFile = false;
+
     for (int tries = 0; tries < 3; tries++)
     {
-        if (QFile::exists(configFilename))
+        /* Search all mountpoints, as on some systems FAT partition
+           may not be first volume */
+        for (auto mp : mountpoints)
+        {
+            folder = QString::fromStdString(mp);
+            if (!folder.isEmpty() && folder.back() == '\\')
+                folder.chop(1);
+            configFilename = folder+"/config.txt";
+
+            if (QFile::exists(configFilename))
+            {
+                foundFile = true;
+                break;
+            }
+        }
+        if (foundFile)
             break;
         QThread::sleep(1);
     }
 
-    if (!QFile::exists(configFilename))
+    if (!foundFile)
     {
         emit error(tr("Unable to customize. File '%1' does not exist.").arg(configFilename));
         return false;