GtkFileChooserDialog上的gtk_widget_destroy导致分段错误

Question

我的第一个GTK +应用程序有问题。我试图实现保存到XML文件。它按应有的方式工作，但有时，该程序会因分段错误而在gtk_widget_destroy（save_dialog）崩溃。我真的不知道为什么会这样。

我希望有人可以帮助我。

功能代码：

static void save_file_from_source_view(gboolean is_save_as)
{
  GtkTextIter start, end;
  char *text_content;

  gtk_text_buffer_get_start_iter(GTK_TEXT_BUFFER(text_editor_buffer), &start);
  gtk_text_buffer_get_end_iter(GTK_TEXT_BUFFER(text_editor_buffer), &end);
  text_content = gtk_text_buffer_get_text(GTK_TEXT_BUFFER(text_editor_buffer), &start, &end, FALSE);

  if(is_save_as||last_filename==NULL)
  {
    GtkWidget *save_dialog;
    gint result;

    save_dialog = gtk_file_chooser_dialog_new("Save File", GTK_WINDOW(window), GTK_FILE_CHOOSER_ACTION_SAVE, "Cancel", GTK_RESPONSE_CANCEL, "Save", GTK_RESPONSE_ACCEPT, NULL);
    gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(save_dialog), TRUE);
    gtk_file_chooser_set_current_name(GTK_FILE_CHOOSER(save_dialog), last_filename!=NULL? last_filename:"untitled.xml");
    result = gtk_dialog_run(GTK_DIALOG(save_dialog));
    if(result == GTK_RESPONSE_ACCEPT)
    {
      char *filename;
      filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(save_dialog));
      save_file(filename, text_content);
      g_free(last_filename);
      last_filename = malloc(sizeof(filename));
      g_print("Got here 1\n");
      strcpy(last_filename, filename);
      g_print("Got here 2\n");
      g_free(filename);
      g_print("Got here 3\n");
    }
    g_print("Got here 4\n");
    gtk_widget_destroy(save_dialog); // Crashes here
    g_print("Got here 5\n");
  }
  else
  {
    save_file(last_filename, text_content);
  }
}

输出：

Got here 1
Got here 2
Got here 3
Got here 4
Segemntation fault (core dumped)

Answer 1

请确保您想要字符串的长度：

last_filename = malloc(strlen(filename) + 1);

而不是指向char的指针的大小（如您所做的：：

last_filename = malloc(sizeof(filename));

为了避免内存泄漏，请不要忘记最后调用free(last_filename)。