Fix crash on saving new file (severe)

gui.py

@@ -339,11 +339,11 @@ class DocumentWindow(QMainWindow):
     def menuFileSaveAction(self):
         self.updateDocument()
 
-        fileExt = os.path.splitext(self.currentFilePath)[1].lower()
-
-        if self.currentFilePath and fileExt != ".cma":
-            # Chordsheet Macro files can't be saved at this time
-            self.saveFile(self.currentFilePath)
+        if self.currentFilePath:
+            fileExt = os.path.splitext(self.currentFilePath)[1].lower()
+            if fileExt != ".cma":
+                # Chordsheet Macro files can't be saved at this time
+                self.saveFile(self.currentFilePath)
         else:
             filePath = QFileDialog.getSaveFileName(self.window.tabWidget, 'Save file', self.getPath(
                 "workingPath"), "Chordsheet ML files (*.xml *.cml)")[0]