X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=ncurses%2Fbase%2Flib_bkgd.c;h=1dcae90d6ad955c1576f46a556fb54635d078a18;hp=2030030f91a5255ec3192bf75eccb6cb3b538c76;hb=790a85dbd4a81d5f5d8dd02a44d84f01512ef443;hpb=47d2fb4537d9ad5bb14f4810561a327930ca4280

diff --git a/ncurses/base/lib_bkgd.c b/ncurses/base/lib_bkgd.c
index 2030030f..1dcae90d 100644
--- 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);