- made --shellvars into --shellvar and make it only one list of commands passed to the Tcl. The list is separated by comma but without spaces. The variables are accessed in Tcl with the names shellvar_x where x is the index in the list of command comma separated values

- fixed an issue in the TclShell that generated an exception IndexError which crashed the software

flatcamTools/ToolShell.py

@@ -142,10 +142,13 @@ class TermWidget(QWidget):
         self._append_to_browser('in', '> ' + text + '\n')
 
         if len(self._history) < 2 or self._history[-2] != text:  # don't insert duplicating items
-            if text[-1] == '\n':
-                self._history.insert(-1, text[:-1])
-            else:
-                self._history.insert(-1, text)
+            try:
+                if text[-1] == '\n':
+                    self._history.insert(-1, text[:-1])
+                else:
+                    self._history.insert(-1, text)
+            except IndexError:
+                return
 
         self._historyIndex = len(self._history) - 1