X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=ncurses%2Fbase%2Flib_addch.c;h=a144328936c1b9765897361009a89252d7ae482a;hp=fdb26415b205c32ac0c91e21c86ab1c2f294a40a;hb=0af9283ca273c267ee6036c3b88115d9ba6d55a6;hpb=b116355ab2af379e49fd0be31bdd440fc14fd902

diff --git a/ncurses/base/lib_addch.c b/ncurses/base/lib_addch.c
index fdb26415..a1443289 100644
--- a/ncurses/base/lib_addch.c
+++ b/ncurses/base/lib_addch.c
@@ -1,5 +1,6 @@
 /****************************************************************************
- * Copyright (c) 1998-2017,2019 Free Software Foundation, Inc.              *
+ * 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  *
  * copy of this software and associated documentation files (the            *
@@ -36,7 +37,7 @@
 #include <curses.priv.h>
 #include <ctype.h>
 
-MODULE_ID("$Id: lib_addch.c,v 1.133 2019/05/11 19:51:02 tom Exp $")
+MODULE_ID("$Id: lib_addch.c,v 1.138 2021/06/17 21:11:08 tom Exp $")
 
 static const NCURSES_CH_T blankchar = NewChar(BLANK_TEXT);
 
@@ -139,7 +140,7 @@ newline_forces_scroll(WINDOW *win, NCURSES_SIZE_T *ypos)
  * wrapped the cursor.  We don't do anything with this flag except set it when
  * wrapping, and clear it whenever we move the cursor.  If we try to wrap at
  * the lower-right corner of a window, we cannot move the cursor (since that
- * wouldn't be legal).  So we return an error (which is what SVr4 does). 
+ * wouldn't be legal).  So we return an error (which is what SVr4 does).
  * Unlike SVr4, we can successfully add a character to the lower-right corner
  * (Solaris 2.6 does this also, however).
  */
@@ -207,6 +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;