(mbswidth): Add a flags argument.

(mbswidth): New declaration.
(MBSW_ACCEPT_INVALID, MBSW_ACCEPT_UNPRINTABLE): New macros.

1 files changed, 16 insertions, 1 deletions

diff --git a/lib/mbswidth.h b/lib/mbswidth.h
index 1ef47d622..f76021b93 100644
--- a/lib/mbswidth.h
+++ b/lib/mbswidth.h
@@ -23,4 +23,19 @@
 # endif
 #endif
 
-extern int mbswidth PARAMS ((const char *string));
+/* Optional flags to influence mbswidth/mbsnwidth behavior.  */
+
+/* Assume invalid characters have width 0.  If this is not set, the
+   functions return -1 if an invalid or incomplete character occurs.  */
+#define MBSW_ACCEPT_INVALID		1
+
+/* Assume unprintable characters have width 1.  If this is not set, the
+   functions return -1 if a non-printable character occurs.  */
+#define MBSW_ACCEPT_UNPRINTABLE	2
+
+/* Returns the number of screen columns needed for STRING.  */
+extern int mbswidth PARAMS ((const char *string, int flags));
+
+/* Returns the number of screen columns needed for the NBYTES bytes
+   starting at BUF.  */
+extern int mbsnwidth PARAMS ((const char *buf, size_t nbytes, int flags));