fixed potential bug in IS_SET().

st.c

@@ -34,7 +34,7 @@
 #define BETWEEN(x, a, b)  ((a) <= (x) && (x) <= (b))
 #define LIMIT(x, a, b)    (x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x)
 #define ATTRCMP(a, b) ((a).mode != (b).mode || (a).fg != (b).fg || (a).bg != (b).bg)
-#define IS_SET(flag) (term.mode & flag)
+#define IS_SET(flag) (term.mode & (flag))
 
 /* Attribute, Cursor, Character state, Terminal mode, Screen draw mode */
 enum { ATTR_NULL=0 , ATTR_REVERSE=1 , ATTR_UNDERLINE=2, ATTR_BOLD=4, ATTR_GFX=8 };