My best guess was to comment out line 455 - if (glist->gl_havewindow) - in the comment_vis method, but that wasn't it, and all the other attempts I did were more gratuitous guesses that led nowhere.
I was close! If I also comment out the if (!glist->gl_havewindow) function set in line 331, it shows up!!!
Now I need more experiments so I can better understand all this. But hey, did it!
Thanks anyway! If anyone has more guides and hints on learning how to code GUIs, I'd appreciate it.
cheers