This patch comes from Debian and was modified by Kei Kebreau <kkebreau@posteo.net>.
Link: https://anonscm.debian.org/cgit/pkg-wmaker/wmfire.git/plain/debian/patches/gdk_updates.patch?h=debian/1.2.4-2&id=a272234fc5eecdbfc469adb12133196bc62f3059

Description: Update for newer versions of GDK.
 In particular, the icon window was not receiving enter and leave events from
 the pointer.  To fix this, we get rid of the second GdkWindow iconwin entirely
 and set win to be its own icon.
 .
 This also removes the need for the "broken window manager" fix, so we remove it
 and all references to it.
Author: Doug Torrance <dtorrance@piedmont.edu>

diff -ur wmfire-1.2.4.old/src/wmfire.c wmfire-1.2.4/src/wmfire.c
--- wmfire-1.2.4.old/src/wmfire.c	2017-04-23 14:26:58.449487117 -0400
+++ wmfire-1.2.4/src/wmfire.c	2017-04-23 14:32:10.785238671 -0400
@@ -77,7 +77,6 @@
 typedef struct {
 	Display *display;	/* X11 display */
 	GdkWindow *win;		/* Main window */
-	GdkWindow *iconwin;	/* Icon window */
 	GdkGC *gc;		/* Drawing GC */
 	GdkPixmap *pixmap;	/* Main pixmap */
 	GdkBitmap *mask;	/* Dockapp mask */
@@ -141,7 +140,6 @@
 int cmap = 0;
 int lock = 0;
 int proximity = 0;
-int broken_wm = 0;
 
 /******************************************/
 /* Main                                   */
@@ -262,12 +260,8 @@
 		usleep(REFRESH);
 
 		/* Draw the rgb buffer to screen */
-		if (!broken_wm)
-			gdk_draw_rgb_image(bm.iconwin, bm.gc, 4, 4, XMAX, YMAX, GDK_RGB_DITHER_NONE, bm.rgb, XMAX * 3);
-		else
-			gdk_draw_rgb_image(bm.win, bm.gc, 4, 4, XMAX, YMAX, GDK_RGB_DITHER_NONE, bm.rgb, XMAX * 3);
+                gdk_draw_rgb_image(bm.win, bm.gc, 4, 4, XMAX, YMAX, GDK_RGB_DITHER_NONE, bm.rgb, XMAX * 3);
 	}
-
 	return 0;
 }
 
@@ -556,9 +550,7 @@
 #define MASK GDK_BUTTON_PRESS_MASK | GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK | GDK_POINTER_MOTION_HINT_MASK
 
 	GdkWindowAttr attr;
-	GdkWindowAttr attri;
 	Window win;
-	Window iconwin;
 
 	GdkPixmap *icon;
 
@@ -578,10 +570,6 @@
 	attr.wmclass_class = "wmfire";
 	attr.window_type = GDK_WINDOW_TOPLEVEL;
 
-	/* Make a copy for the iconwin - parameters are the same */
-	memcpy(&attri, &attr, sizeof (GdkWindowAttr));
-	attri.window_type = GDK_WINDOW_CHILD;
-
 	sizehints.flags = USSize;
 	sizehints.width = 64;
 	sizehints.height = 64;
@@ -592,18 +580,11 @@
 		exit(1);
 	}
 
-	bm.iconwin = gdk_window_new(bm.win, &attri, GDK_WA_TITLE | GDK_WA_WMCLASS);
-	if (!bm.iconwin) {
-		fprintf(stderr, "FATAL: Cannot make icon window\n");
-		exit(1);
-	}
-
 	win = GDK_WINDOW_XWINDOW(bm.win);
-	iconwin = GDK_WINDOW_XWINDOW(bm.iconwin);
 	XSetWMNormalHints(GDK_WINDOW_XDISPLAY(bm.win), win, &sizehints);
 
 	wmhints.initial_state = WithdrawnState;
-	wmhints.icon_window = iconwin;
+	wmhints.icon_window = win;
 	wmhints.icon_x = 0;
 	wmhints.icon_y = 0;
 	wmhints.window_group = win;
@@ -613,10 +594,8 @@
 
 	bm.pixmap = gdk_pixmap_create_from_xpm_d(bm.win, &(bm.mask), NULL, master_xpm);
 	gdk_window_shape_combine_mask(bm.win, bm.mask, 0, 0);
-	gdk_window_shape_combine_mask(bm.iconwin, bm.mask, 0, 0);
 
 	gdk_window_set_back_pixmap(bm.win, bm.pixmap, False);
-	gdk_window_set_back_pixmap(bm.iconwin, bm.pixmap, False);
 
 #if 0
         gdk_window_set_type_hint(bm.win, GDK_WINDOW_TYPE_HINT_DOCK);
@@ -626,7 +605,6 @@
 #endif
 
 	icon = gdk_pixmap_create_from_xpm_d(bm.win, NULL, NULL, icon_xpm);
-	gdk_window_set_icon(bm.win, bm.iconwin, icon, NULL);
 
 	gdk_window_show(bm.win);
 
@@ -721,9 +699,6 @@
 		case 'l':
 			lock = 1;
 			break;
-		case 'b':
-			broken_wm = 1;
-			break;
 		case 'h':
 		default:
 			do_help();
@@ -766,6 +741,5 @@
 	for (i = 0; i < NFLAMES; i++)
 		fprintf(stderr, "%d:%s ", i + 1, fire[i].text);
 	fprintf(stderr, "\n\t-l\t\t\tlock flame colour and monitor\n");
-	fprintf(stderr, "\t-b\t\t\tactivate broken window manager fix\n");
 	fprintf(stderr, "\t-h\t\t\tprints this help\n");
 }
Only in wmfire-1.2.4/src: wmfire.c~
diff -ur wmfire-1.2.4.old/wmfire.1 wmfire-1.2.4/wmfire.1
--- wmfire-1.2.4.old/wmfire.1	2017-04-23 14:26:58.449487117 -0400
+++ wmfire-1.2.4/wmfire.1	2017-04-23 14:41:20.697186114 -0400
@@ -8,7 +8,6 @@
 
 .SH SYNOPSIS
 .B wmfire
-[-b]
 [-c CPU]
 [-f COLOUR]
 [-F FILE]
@@ -54,9 +53,6 @@
 
 .SH OPTIONS
 .TP
-.B -b
-Activate broken window manager fix (if grey box diplayed)
-.TP
 .B -c [0..3]
 .br
 Monitor SMP CPU number X
