X-Git-Url: http://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=ncurses%2Fbase%2Flib_addch.c;h=378c2881faac5d6d4d689f441d3986dfd5f7b341;hb=6830dca51a4e50d41e7bd114bdbaa857b42a46f4;hp=604b13be8cec16bab2f9242b0006ffe988455b06;hpb=47d2fb4537d9ad5bb14f4810561a327930ca4280;p=ncurses.git

diff --git a/ncurses/base/lib_addch.c b/ncurses/base/lib_addch.c
index 604b13be..378c2881 100644
--- a/ncurses/base/lib_addch.c
+++ b/ncurses/base/lib_addch.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2019,2020 Thomas E. Dickey                                     *
+ * Copyright 2019-2020,2021 Thomas E. Dickey                                *
  * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
  *                                                                          *
  * Permission is hereby granted, free of charge, to any person obtaining a  *
@@ -37,7 +37,7 @@
 #include <curses.priv.h>
 #include <ctype.h>
 
-MODULE_ID("$Id: lib_addch.c,v 1.134 2020/02/02 23:34:34 tom Exp $")
+MODULE_ID("$Id: lib_addch.c,v 1.137 2021/02/20 22:24:34 tom Exp $")
 
 static const NCURSES_CH_T blankchar = NewChar(BLANK_TEXT);
 
@@ -208,6 +208,20 @@ _nc_build_wch(WINDOW *win, ARG_CH_T ch)
     WINDOW_EXT(win, addch_x) = x;
     WINDOW_EXT(win, addch_y) = y;
 
+    /*
+     * If the background character is a wide-character, that may interfere with
+     * processing multibyte characters in this function.
+     */
+    if (!is8bits(CharOf(CHDEREF(ch)))) {
+	if (WINDOW_EXT(win, addch_used) != 0) {
+	    /* discard the incomplete multibyte character */
+	    WINDOW_EXT(win, addch_used) = 0;
+	    TR(TRACE_VIRTPUT,
+	       ("Alert discarded incomplete multibyte"));
+	}
+	return 1;
+    }
+
     init_mb(state);
     buffer[WINDOW_EXT(win, addch_used)] = (char) CharOf(CHDEREF(ch));
     WINDOW_EXT(win, addch_used) += 1;