ncurses 5.9 - patch 20140503

[ncurses.git] / include / tic.h

diff --git a/include/tic.h b/include/tic.h
index 7c90065ccaf29dc585d095dfa8c5a64d5954dc00..528a1b7d5af35849be142e1a12dfcec52b765e53 100644 (file)
--- a/include/tic.h
+++ b/include/tic.h
@@ -33,7 +33,7 @@
  ****************************************************************************/
 
 /*
- * $Id: tic.h,v 1.68 2012/02/18 20:09:19 tom Exp $
+ * $Id: tic.h,v 1.69 2012/03/17 18:22:10 tom Exp $
  *     tic.h - Global variables and structures for the terminfo
  *                     compiler.
  */
@@ -224,6 +224,12 @@ extern NCURSES_EXPORT(const struct alias *) _nc_get_alias_table (bool);
 
 #define NOTFOUND       ((struct name_table_entry *) 0)
 
+/*
+ * The casts are required for correct sign-propagation with systems such as
+ * AIX, IRIX64, Solaris which default to unsigned characters.  The C standard
+ * leaves this detail unspecified.
+ */
+
 /* out-of-band values for representing absent capabilities */
 #define ABSENT_BOOLEAN         ((signed char)-1)       /* 255 */
 #define ABSENT_NUMERIC         (-1)