ncurses 6.1 - patch 20180908

[ncurses.git] / ncurses / tty / tty_update.c

diff --git a/ncurses/tty/tty_update.c b/ncurses/tty/tty_update.c
index fd35c47beb2e2bdd174f365736f70e04ab35ff46..17f641136d8ac165c0e77df8021cfed92cbd4b68 100644 (file)
--- a/ncurses/tty/tty_update.c
+++ b/ncurses/tty/tty_update.c
@@ -84,7 +84,7 @@
 
 #include <ctype.h>
 
-MODULE_ID("$Id: tty_update.c,v 1.298 2018/05/05 19:11:55 tom Exp $")
+MODULE_ID("$Id: tty_update.c,v 1.299 2018/09/08 21:33:59 tom Exp $")
 
 /*
  * This define controls the line-breakout optimization.  Every once in a
@@ -373,9 +373,18 @@ PutAttrChar(NCURSES_SP_DCLx CARG_CH_T ch)
        } else
 #endif
        if (!SP_PARM->_screen_acs_map[c8]) {
+           /*
+            * If we found no mapping for a given alternate-character set item
+            * in the terminal description, attempt to use the ASCII fallback
+            * code which is populated in the _acs_map[] array.  If that did
+            * not correspond to a line-drawing, etc., graphics character, the
+            * array entry would be empty.
+            */
            chtype temp = UChar(SP_PARM->_acs_map[c8]);
-           RemAttr(attr, A_ALTCHARSET);
-           SetChar(my_ch, temp, AttrOf(attr));
+           if (temp) {
+               RemAttr(attr, A_ALTCHARSET);
+               SetChar(my_ch, temp, AttrOf(attr));
+           }
        }
 
        /*