propagate only necessary root flags to TApplication.

src/musrFT.cpp

@@ -1439,15 +1439,17 @@ Int_t main(Int_t argc, Char_t *argv[])
 
     // if Fourier graphical export is whished, switch to batch mode
     Bool_t batch = false;
+    int cc=0;
+    char **arg;
     if (startupParam.graphicFormat.Length() != 0) {
       batch = true;
-      argv[argc] = (Char_t*)malloc(16*sizeof(Char_t));
-      strcpy(argv[argc], "-b");
-      argc++;
+      arg[cc] = (Char_t*)malloc(16*sizeof(Char_t));
+      strcpy(arg[cc], "-b");
+      cc++;
     }
 
     // plot the Fourier transform
-    TApplication app("App", &argc, argv);
+    TApplication app("App", &cc, arg);
 
     if (startupHandler) {
       fourierCanvas = std::unique_ptr<PFourierCanvas>(new PFourierCanvas(fourier, dataSetTag, startupParam.title.Data(),