--- rxvt-unicode/src/rxvt.h	2010/04/01 00:41:07	1.395
+++ rxvt-unicode/src/rxvt.h	2010/04/01 01:03:20	1.398
@@ -306,28 +306,18 @@
   SECONDARY,
 };
 
+// define various rendition bits and masks. the rendition word
+// is 32 bits in size, and we should use it as efficiently as possible
+
 #define RS_None                 0
 
+// GET_BGATTR depends on RS_fgShift > RS_bgShift
 #define RS_colorMask		((1UL << Color_Bits) - 1UL)
 #define RS_bgShift		0
 #define RS_fgShift		(RS_bgShift + Color_Bits)
 #define RS_bgMask               (RS_colorMask << RS_bgShift)
 #define RS_fgMask               (RS_colorMask << RS_fgShift)
 
-// font styles
-#define RS_Bold                 0x08000000UL    // value 1
-#define RS_Italic		0x10000000UL    // value 2
-
-// fake styles
-#define RS_Blink                0x20000000UL    // blink
-#define RS_RVid                 0x40000000UL    // reverse video
-#define RS_Uline                0x80000000UL    // underline
-
-// 5 custom bits for extensions
-#define RS_customCount          16UL
-#define RS_customShift          23
-#define RS_customMask           ((RS_customCount - 1UL) << RS_customShift)
-
 // must have space for rxvt_fontset::fontCount * 2 + 2 values
 #define RS_fontShift            (RS_fgShift + Color_Bits)
 #define RS_Careful		(1UL << RS_fontShift)	/* be careful when drawing these */
@@ -336,9 +326,23 @@
 // toggle this to force redraw, must be != RS_Careful and otherwise "pretty neutral"
 #define RS_redraw		(2UL << RS_fontShift)
 
+// 5 custom bits for extensions
+#define RS_customCount          16UL
+#define RS_customShift          23
+#define RS_customMask           ((RS_customCount - 1UL) << RS_customShift)
+
+// font styles
+#define RS_Bold                 (1UL << RS_styleShift)
+#define RS_Italic		(2UL << RS_styleShift)
+
 #define RS_styleCount		4
-#define RS_styleMask		(RS_Bold | RS_Italic)
 #define RS_styleShift		27
+#define RS_styleMask		(RS_Bold | RS_Italic)
+
+// fake styles
+#define RS_Blink                (1UL << 29)
+#define RS_RVid                 (1UL << 30)    // reverse video
+#define RS_Uline                (1UL << 31)    // underline
 
 #define RS_baseattrMask         (RS_Italic | RS_Bold | RS_Blink | RS_RVid | RS_Uline)
 #define RS_attrMask             (RS_baseattrMask | RS_fontMask)
@@ -639,10 +643,13 @@
 #define SET_STYLE(x,style)	(((x) & ~RS_styleMask) | ((style) << RS_styleShift))
 
 #define GET_ATTR(x)             (((x) & RS_attrMask))
-#define GET_BGATTR(x)                                                   \
-    (((x) & RS_RVid) ? (((x) & (RS_attrMask & ~RS_RVid))                \
-                        | (((x) & RS_colorMask) << RS_bgShift))              \
-                     : ((x) & (RS_attrMask | RS_bgMask)))
+// return attributes defining the background, encoding doesn't matter
+// depends on RS_fgShift > RS_bgShift
+#define GET_BGATTR(x)                                      \
+  (expect_false ((x) & RS_RVid)                            \
+    ? (((x) & (RS_attrMask & ~RS_RVid))                    \
+      | (((x) & RS_fgMask) >> (RS_fgShift - RS_bgShift)))  \
+    : ((x) & (RS_attrMask | RS_bgMask)))
 #define SET_FGCOLOR(x,fg)       (((x) & ~RS_fgMask)   | ((fg) << RS_fgShift))
 #define SET_BGCOLOR(x,bg)       (((x) & ~RS_bgMask)   | ((bg) << RS_bgShift))
 #define SET_ATTR(x,a)           (((x) & ~RS_attrMask) | (a))