xfwm4: treat black label as a special case

Otherwise it is the same as gray, because it isn't really a color in HSV
color scale.

QubesOS/qubes-issues#2120

xfwm4/xfwm4-4.12.3-qubes-decoration-black-hack.patch

@@ -0,0 +1,18 @@
+Index: xfwm4-4.12.3/src/mypixmap.c
+===================================================================
+--- xfwm4-4.12.3.orig/src/mypixmap.c
++++ xfwm4-4.12.3/src/mypixmap.c
+@@ -612,7 +612,12 @@ pixbuf_create_from_xpm (gpointer handle,
+                     1.0*color->green/0xFFFF,
+                     1.0*color->blue/0xFFFF,
+                     &h, &s, &v);
+-            gtk_hsv_to_rgb(override_h, override_s, v, &new_r, &new_g, &new_b);
++            /* Special case for black label, otherwise it is the same as gray -
++             * see #2120 */
++            if (override_h == 0.0 && override_s == 0.0 && override_v == 0.0)
++                gtk_hsv_to_rgb(override_h, override_s, v * 0.2, &new_r, &new_g, &new_b);
++            else
++                gtk_hsv_to_rgb(override_h, override_s, v, &new_r, &new_g, &new_b);
+             color->red = new_r*0xFFFF;
+             color->green = new_g*0xFFFF;
+             color->blue = new_b*0xFFFF;

xfwm4/xfwm4.spec

@@ -22,6 +22,7 @@ Patch20:	xfwm4-4.6.1-cleanup-idle-queue.patch
 
 Patch100:	xfwm4-4.12.3-qubes-decoration.patch
 Patch101:	xfwm4-4.12.3-qubes-decoration-custom-colors.patch
+Patch102:	xfwm4-4.12.3-qubes-decoration-black-hack.patch
 
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
@@ -49,6 +50,7 @@ xfwm4 is a window manager compatible with GNOME, GNOME2, KDE2, KDE3 and Xfce.
 
 %patch100 -p1 -b .qubes
 %patch101 -p1 -b .qubes-custom-color
+%patch102 -p1 -b .qubes-black-hack
 
 
 %build