ncurses 6.2 - patch 20200531

[ncurses.git] / ncurses / base / lib_bkgd.c

diff --git a/ncurses/base/lib_bkgd.c b/ncurses/base/lib_bkgd.c
index 2030030f91a5255ec3192bf75eccb6cb3b538c76..1dcae90d6ad955c1576f46a556fb54635d078a18 100644 (file)
--- a/ncurses/base/lib_bkgd.c
+++ b/ncurses/base/lib_bkgd.c
@@ -37,7 +37,9 @@
 
 #include <curses.priv.h>
 
-MODULE_ID("$Id: lib_bkgd.c,v 1.54 2020/02/02 23:34:34 tom Exp $")
+MODULE_ID("$Id: lib_bkgd.c,v 1.55 2020/03/02 01:34:48 tom Exp $")
+
+static const NCURSES_CH_T blank = NewChar(BLANK_TEXT);
 
 /*
  * Set the window's background information.
@@ -143,6 +145,14 @@ wbkgrnd(WINDOW *win, const ARG_CH_T ch)
            SetPair(new_bkgd, 0);
        }
 
+       /* avoid setting background-character to a null */
+       if (CharOf(new_bkgd) == 0) {
+           NCURSES_CH_T tmp_bkgd = blank;
+           SetAttr(tmp_bkgd, AttrOf(new_bkgd));
+           SetPair(tmp_bkgd, GetPair(new_bkgd));
+           new_bkgd = tmp_bkgd;
+       }
+
        memset(&old_bkgd, 0, sizeof(old_bkgd));
        (void) wgetbkgrnd(win, &old_bkgd);