Some windows don't play nicely with xcb_ewmh

[qsmodo]

I've set #define OUTPUT_TITLE True in my config.h, recompiled, but still no title is output.

I added a debugging fprintf(stderr, "%s\n", wtitle.strings); statement inside this test:

FrankenWM/frankenwm.c

Lines 1385 to 1388 in 0eb3d54

	if (M_CURRENT) {
	cookie = xcb_ewmh_get_wm_name_unchecked(ewmh, M_CURRENT->win);
	xcb_ewmh_get_wm_name_reply(ewmh, cookie, &wtitle, (void *)0);
	}

and found out that the output is (null). It seems something is wrong with handling that string.

[qsmodo]

Okay, it turns out this is a more over-reaching issue. Not all windows respond to xcb_ewmh_get_wm_name, especially old ones as xterm, xmessage, gvim, and probably many others. This also means that rules[] also fails for matching those windows. Indeed,

FrankenWM/frankenwm.c

Lines 2063 to 2064 in 0eb3d54

	if (xcb_ewmh_get_wm_name_reply(ewmh, cookie, &wtitle, (void *)0)) {
	DEBUGP("EWMH window title: %s\n", wtitle.strings);

prints garbage or is skipped altogether for such windows.

Spectrwm works correctly in this regard, and it uses xcb_icccm functions, not xcb_ewmh, so probably that's the problem.

[qsmodo]

So, with the PR merge the largest problem is gone. Now there is the output title issue left.

What I have managed to do is in this branch. At first sight it seems to work well, the title is output for all windows. But if the title contains non-ASCII characters, it may get cropped or mangled. As it turns out, the Xlib uses some obscure COMPOUND_TEXT and converting it to UTF-8 is as obscure and tricky (see this thread).

The options, as I see it, are

1. Leave this thing alone and allow OUTPUT_TITLE not to work.
2. Merge that branch, and now OUTPUT_TITLE more or less works, but the window title may get mangled.
3. Delete OUTPUT_TITLE altogether and use xdotool getactivewindow getwindowname.

Honestly option 3 looks the best to me. I have been using it for a couple of months in my Dzen bar and it works flawlessly. It also avoids duplicating code.