Clear partition names better & for USB (#461)

Fixes #456

Author: procount

recovery/multiimagewritethread.cpp

@@ -275,6 +275,14 @@ void MultiImageWriteThread::run()
     if (!writePartitionTable(_drive, partitionMap))
         return;
 
+    /* Zero out first sector of partitions, to make sure to get rid of previous file system (label) */
+    emit statusUpdate(tr("Zero'ing start of each partition"));
+    foreach (PartitionInfo *p, partitionMap.values())
+    {
+        if (p->partitionSizeSectors())
+            QProcess::execute("/bin/dd count=3 bs=512 if=/dev/zero of="+p->partitionDevice());
+    }
+
     /* Write partition table to boot drive (if using multiple drives) */
     if (_multiDrives)
     {
@@ -283,6 +291,14 @@ void MultiImageWriteThread::run()
         if (!writePartitionTable(_bootdrive, bootPartitionMap))
             return;
 
+        /* Zero out first sector of partitions, to make sure to get rid of previous file system (label) */
+        emit statusUpdate(tr("Zero'ing start of each partition"));
+        foreach (PartitionInfo *p, bootPartitionMap.values())
+        {
+            if (p->partitionSizeSectors())
+                QProcess::execute("/bin/dd count=3 bs=512 if=/dev/zero of="+p->partitionDevice());
+        }
+
         if (QProcess::execute("mount -t ext4 "+partdev(_bootdrive, SETTINGS_PARTNR)+" /mnt2") == 0)
         {
             QFile f("/mnt2/installed_os.json");
@@ -293,14 +309,6 @@ void MultiImageWriteThread::run()
         }
     }
 
-    /* Zero out first sector of partitions, to make sure to get rid of previous file system (label) */
-    emit statusUpdate(tr("Zero'ing start of each partition"));
-    foreach (PartitionInfo *p, partitionMap.values())
-    {
-        if (p->partitionSizeSectors())
-            QProcess::execute("/bin/dd count=1 bs=512 if=/dev/zero of="+p->partitionDevice());
-    }
-
     /* Install each operating system */
     foreach (OsInfo *image, _images)
     {