diff --git a/test/combine.c b/test/combine.c
new file mode 100644
index 0000000..eca72b8
--- /dev/null
+++ b/test/combine.c
@@ -0,0 +1,313 @@
+/****************************************************************************
+ * Copyright 2021,2022 Thomas E. Dickey                                     *
+ *                                                                          *
+ * Permission is hereby granted, free of charge, to any person obtaining a  *
+ * copy of this software and associated documentation files (the            *
+ * "Software"), to deal in the Software without restriction, including      *
+ * without limitation the rights to use, copy, modify, merge, publish,      *
+ * distribute, distribute with modifications, sublicense, and/or sell       *
+ * copies of the Software, and to permit persons to whom the Software is    *
+ * furnished to do so, subject to the following conditions:                 *
+ *                                                                          *
+ * The above copyright notice and this permission notice shall be included  *
+ * in all copies or substantial portions of the Software.                   *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
+ *                                                                          *
+ * Except as contained in this notice, the name(s) of the above copyright   *
+ * holders shall not be used in advertising or otherwise to promote the     *
+ * sale, use or other dealings in this Software without prior written       *
+ * authorization.                                                           *
+ ****************************************************************************/
+/*
+ * $Id: combine.c,v 1.23 2022/12/10 22:28:50 tom Exp $
+ */
+
+#include <test.priv.h>
+
+#if USE_WIDEC_SUPPORT
+
+#include <wctype.h>
+#include <dump_window.h>
+#include <popup_msg.h>
+
+static int c_opt;
+static int r_opt;
+
+static int
+next_char(int value)
+{
+    do {
+	++value;
+    } while (!iswprint((wint_t) value));
+    return value;
+}
+
+static int
+prev_char(int value)
+{
+    do {
+	--value;
+    } while (!iswprint((wint_t) value));
+    return value;
+}
+
+static void
+do_row(int row, int base_ch, int over_ch)
+{
+    int col = 0;
+    bool done = FALSE;
+    bool reverse = (r_opt && !(row % 2));
+
+    move(row, col);
+    printw("[U+%04X]", over_ch);
+    do {
+	if (c_opt) {
+	    wchar_t source[2];
+	    cchar_t target;
+	    attr_t attr = reverse ? A_REVERSE : A_NORMAL;
+
+	    source[1] = 0;
+
+	    source[0] = (wchar_t) base_ch;
+	    setcchar(&target, source, attr, 0, NULL);
+	    add_wch(&target);
+
+	    source[0] = (wchar_t) over_ch;
+	    setcchar(&target, source, attr, 0, NULL);
+	    add_wch(&target);
+	} else {
+	    wchar_t data[3];
+
+	    data[0] = (wchar_t) base_ch;
+	    data[1] = (wchar_t) over_ch;
+	    data[2] = 0;
+	    if (reverse)
+		attr_on(A_REVERSE, NULL);
+	    addwstr(data);
+	    if (reverse)
+		attr_off(A_REVERSE, NULL);
+	}
+	col = getcurx(stdscr);
+	base_ch = next_char(base_ch);
+	done = (col + 1 >= COLS);
+    } while (!done);
+}
+
+#define LAST_OVER 0x6f
+
+static int
+next_over(int value)
+{
+    if (++value > LAST_OVER)
+	value = 0;
+    return value;
+}
+
+static int
+prev_over(int value)
+{
+    if (--value < 0)
+	value = LAST_OVER;
+    return value;
+}
+
+static void
+do_all(int left_at, int over_it)
+{
+    int row;
+
+    for (row = 0; row < LINES; ++row) {
+	do_row(row, left_at, 0x300 + over_it);
+	over_it = next_over(over_it);
+    }
+}
+
+static void
+show_help(WINDOW *current)
+{
+    /* *INDENT-OFF* */
+    static struct {
+	int	key;
+	CONST_FMT char * msg;
+    } help[] = {
+	{ HELP_KEY_1,	"Show this screen" },
+	{ CTRL('L'),	"Repaint screen" },
+	{ '$',		"Scroll to end of combining-character range" },
+	{ '+',		"Scroll to next combining-character in range" },
+	{ KEY_DOWN,	"(same as \"+\")" },
+	{ '-',		"Scroll to previous combining-character in range" },
+	{ KEY_UP,	"(same as \"-\")" },
+	{ '0',		"Scroll to beginning of combining-character range" },
+	{ 'c',		"Toggle command-line option \"-c\"" },
+	{ 'd',		"Dump screen using scr_dump unless \"-l\" option used" },
+	{ 'h',		"Scroll test-data left one column" },
+	{ 'j',		"Scroll test-data down one row" },
+	{ 'k',		"Scroll test-data up one row" },
+	{ 'l',		"Scroll test-data right one column" },
+	{ 'q',		"Quit" },
+	{ ESCAPE,	"(same as \"q\")" },
+	{ QUIT,		"(same as \"q\")" },
+	{ 'r',		"Toggle command-line option \"-r\"" },
+    };
+    /* *INDENT-ON* */
+
+    char **msgs = typeCalloc(char *, SIZEOF(help) + 3);
+    size_t s;
+    int d = 0;
+
+    msgs[d++] = strdup("Test diacritic combining-characters range "
+		       "U+0300..U+036F");
+    msgs[d++] = strdup("");
+    for (s = 0; s < SIZEOF(help); ++s) {
+	char *name = strdup(keyname(help[s].key));
+	size_t need = (11 + strlen(name) + strlen(help[s].msg));
+	msgs[d] = typeMalloc(char, need);
+	_nc_SPRINTF(msgs[d], _nc_SLIMIT(need) "%-10s%s", name, help[s].msg);
+	free(name);
+	++d;
+    }
+    popup_msg2(current, msgs);
+    for (s = 0; msgs[s] != 0; ++s) {
+	free(msgs[s]);
+    }
+    free(msgs);
+}
+
+static void
+usage(int ok)
+{
+    static const char *msg[] =
+    {
+	"Usage: combine [options]"
+	,""
+	,USAGE_COMMON
+	,"Demonstrate combining-characters."
+	,""
+	,"Options:"
+	," -c       use cchar_t data rather than wchar_t string"
+	," -l FILE  log window-dumps to this file"
+	," -r       draw even-numbered rows in reverse-video"
+    };
+    unsigned n;
+    for (n = 0; n < SIZEOF(msg); ++n) {
+	fprintf(stderr, "%s\n", msg[n]);
+    }
+    ExitProgram(ok ? EXIT_SUCCESS : EXIT_FAILURE);
+}
+/* *INDENT-OFF* */
+VERSION_COMMON()
+/* *INDENT-ON* */
+
+int
+main(int argc, char *argv[])
+{
+    int ch;
+    int left_at = ' ';
+    int over_it = 0;
+    bool done = FALSE;
+    bool log_option = FALSE;
+    const char *dump_log = "combine.log";
+
+    while ((ch = getopt(argc, argv, OPTS_COMMON "cl:r")) != -1) {
+	switch (ch) {
+	case 'c':
+	    c_opt = TRUE;
+	    break;
+	case 'l':
+	    log_option = TRUE;
+	    if (!open_dump(optarg))
+		usage(FALSE);
+	    break;
+	case 'r':
+	    r_opt = TRUE;
+	    break;
+	case OPTS_VERSION:
+	    show_version(argv);
+	    ExitProgram(EXIT_SUCCESS);
+	default:
+	    usage(ch == OPTS_USAGE);
+	    /* NOTREACHED */
+	}
+    }
+
+    setlocale(LC_ALL, "");
+    initscr();
+    cbreak();
+    noecho();
+    keypad(stdscr, TRUE);
+
+    do {
+	do_all(left_at, over_it);
+	switch (getch()) {
+	case HELP_KEY_1:
+	    show_help(stdscr);
+	    break;
+	case 'q':
+	case QUIT:
+	case ESCAPE:
+	    done = TRUE;
+	    break;
+	case CTRL('L'):
+	    redrawwin(stdscr);
+	    break;
+	case 'd':
+	    if (log_option)
+		dump_window(stdscr);
+#if HAVE_SCR_DUMP
+	    else
+		scr_dump(dump_log);
+#endif
+	    break;
+	case 'h':
+	    if (left_at > ' ')
+		left_at = prev_char(left_at);
+	    break;
+	case 'l':
+	    left_at = next_char(left_at);
+	    break;
+	case 'c':
+	    c_opt = !c_opt;
+	    break;
+	case 'r':
+	    r_opt = !r_opt;
+	    break;
+	case KEY_HOME:
+	case '0':
+	    over_it = 0;
+	    break;
+	case KEY_END:
+	case '$':
+	    over_it = LAST_OVER;
+	    break;
+	case KEY_UP:
+	case 'k':
+	case '-':
+	    over_it = prev_over(over_it);
+	    break;
+	case KEY_DOWN:
+	case 'j':
+	case '+':
+	    over_it = next_over(over_it);
+	    break;
+	}
+    } while (!done);
+
+    endwin();
+
+    ExitProgram(EXIT_SUCCESS);
+}
+#else
+int
+main(void)
+{
+    printf("This program requires wide-curses functions\n");
+    ExitProgram(EXIT_FAILURE);
+}
+#endif