x11-wm/twm: generate synthetic WM hints when needed

This is based on a patch from Reddit -- the patch on Reddit is in
context-diff form and contains a bunch of cruft, so it's been
re-done (in add_window.c ; the util.c part is used unchanged).
Tested by running Chrome in previous twm -- no drop-downs at
all -- and in this lightly patched one, where it does behave.

PR:		252873
Obtained from:	Reddit

x11-wm/twm/Makefile

@@ -1,5 +1,6 @@
 PORTNAME=	twm
 PORTVERSION=	1.0.11
+PORTREVISION=	1
 CATEGORIES=	x11-wm
 
 MAINTAINER=	x11@FreeBSD.org

x11-wm/twm/files/patch-src_add__window.c

@@ -0,0 +1,12 @@
+--- src/add_window.c.orig	2020-06-14 23:58:19 UTC
++++ src/add_window.c
+@@ -238,6 +238,9 @@ AddWindow(Window w, int iconm, IconMgr *iconp)
+
+     tmp_win->wmhints = XGetWMHints(dpy, tmp_win->w);
+
++    if (!tmp_win->wmhints) {
++        tmp_win->wmhints = gen_synthetic_wmhints(tmp_win);
++    }
+     if (tmp_win->wmhints) {
+         if (restore_iconified) {
+             tmp_win->wmhints->initial_state = IconicState;

x11-wm/twm/files/patch-src_util.c

@@ -0,0 +1,47 @@
+--- src/util.c.orig	2020-06-14 23:58:19 UTC
++++ src/util.c
+@@ -1033,3 +1033,44 @@ Bell(int type _X_UNUSED, int percent, Window win _X_UN
+ #endif
+     return;
+ }
++
++/*
++ * Create synthetic WM_HINTS info for windows.  When a window specifies
++ * stuff, we should probably pay attention to it (though we don't
++ * always; x-ref comments in AddWindow() especially about focus).
++ * However, when it doesn't tell us anything at all, we should assume
++ * something useful.  "Window managers are free to assume convenient
++ * values for all fields of the WM_HINTS property if a window is mapped
++ * without one."  (ICCCM Ch. 4,
++ * <https://www.x.org/releases/X11R7.7/doc/xorg-docs/icccm/icccm.html#Client_Properties>).
++ *
++ * Specifically, we assume it wants us to give it focus.  It's fairly
++ * bogus for a window not to tell us anything, but e.g current versions
++ * of Chrome do (don't do) just that.  So we better make up something
++ * useful.
++ *
++ * Should probably be some configurability for this, so make the func
++ * take the window, even though we don't currently do anything useful
++ * with it...
++ */
++XWMHints *
++gen_synthetic_wmhints(TwmWindow *win)
++{
++	XWMHints *hints;
++
++	hints = XAllocWMHints();
++	if(!hints) {
++		return NULL;
++	}
++
++	/*
++	 * Reasonable defaults.  Takes input, in normal state.
++	 *
++	 * XXX Make configurable?
++	 */
++	hints->flags = InputHint | StateHint;
++	hints->input = True;
++	hints->initial_state = NormalState;
++
++	return hints;
++}

x11-wm/twm/files/patch-src_util.h

@@ -0,0 +1,11 @@
+--- src/util.h.orig	2020-06-14 23:58:19 UTC
++++ src/util.h
+@@ -88,6 +88,8 @@ extern Status I18N_GetIconName(Display *dpy, Window wi
+ extern void SetFocus(TwmWindow *tmp_win, Time time);
+ extern void Bell(int type, int percent, Window win);
+
++extern XWMHints *gen_synthetic_wmhints(TwmWindow *win);
++
+ extern int HotX, HotY;
+
+ #define WM_BELL                 0