work around ROOT error that crashes foton

src/gui/filterwiz/TLGFilterWizard.cc

@@ -859,6 +859,7 @@ TLGFilterWizWindow::FileErrorIndication(Bool_t error)
 
       //--------  Command text-box
       fCommand = new TLGTextEdit (fG[3], 10, 10, kCommandId);
+      fCommand->Clear();
       fCommand->Associate (this);
       fG[3]->AddFrame (fCommand, 0);
 
@@ -1046,6 +1047,7 @@ TLGFilterWizWindow::FileErrorIndication(Bool_t error)
       {
          if (strcmp (name, ".") && strcmp(name, "..")) 
 	 {
+            printf("Checking file %s... ", name);
             // found a file: open it and check magic token
             string fullname = string (dir) + "/" + name;
             ifstream inp (fullname.c_str());
@@ -1053,8 +1055,10 @@ TLGFilterWizWindow::FileErrorIndication(Bool_t error)
             inp.read (line, lMagic);
             if (inp && (strncmp (line, kMagic, lMagic) == 0)) 
 	    {
+               printf("Added\n");
                nlist.push_back (name);
             }
+            printf("Ignored\n");
          }
       }
       gSystem->FreeDirectory(dirp);
@@ -1916,6 +1920,7 @@ TLGFilterWizWindow::FileErrorIndication(Bool_t error)
       }
       if ((fCurSections.size() != 1) && (fCurDesignActive || force)) 
       {
+         fCommand->Clear();
          // Set the state of the GUI widgets for multiple selected sections.
          fCommand->LoadBuffer (" ");
          fCommand->SetState (kFALSE);

src/gui/ligogui/TLGTextEditor.cc

@@ -81,8 +81,32 @@ namespace ligogui {
       //   newline characters), removes the funky tab padding characters
       //   and reformats it into a STL string.
       //
-      TString txt = GetText()->AsString();
-      int N = txt.Length();
+
+      // work-around GetText()->AsString(), which is buggy.
+
+      auto text_block = GetText();
+
+      // AsString() is broken.  The only public access is
+      // TGText::GetChar()
+
+      TGLongPosition pos(0,0);
+      char c;
+      std::string txt = "";
+      while((c = text_block->GetChar(pos)) >= 0)
+      {
+        do {
+          if(c != cmt) {
+            txt += c;
+          }
+          pos.fX += 1;
+        } while((c = text_block->GetChar(pos)) >= 0 && c != cmt);
+        pos.fX = 0;
+        pos.fY += 1;
+        txt += '\n';
+      }
+
+
+      int N = txt.length();
 
       std::string cmd;
       cmd.reserve(N);