Add a test for glyph names

This verifies that hb_font_get_glyph_name
returns false for nonexisting glyphs.
diff --git a/test/api/Makefile.am b/test/api/Makefile.am
index c021eca..950b738 100644
--- a/test/api/Makefile.am
+++ b/test/api/Makefile.am
@@ -45,6 +45,7 @@
 	test-extents \
 	test-font \
 	test-font-scale \
+	test-glyph-names \
 	test-instance-cff2 \
 	test-map \
 	test-object \
diff --git a/test/api/meson.build b/test/api/meson.build
index dd23fc7..ab2ab1e 100644
--- a/test/api/meson.build
+++ b/test/api/meson.build
@@ -18,6 +18,7 @@
   'test-extents.c',
   'test-font.c',
   'test-font-scale.c',
+  'test-glyph-names.c',
   'test-instance-cff2.c',
   'test-map.c',
   'test-object.c',
diff --git a/test/api/test-glyph-names.c b/test/api/test-glyph-names.c
new file mode 100644
index 0000000..48ca06b
--- /dev/null
+++ b/test/api/test-glyph-names.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright © 2023 Red Hat, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Author(s): Matthias Clasen
+ */
+
+#include "hb-test.h"
+
+static void
+test_glyph_names_post (void)
+{
+  hb_face_t *face;
+  hb_font_t *font;
+  hb_bool_t ret;
+  char name [64];
+
+  face = hb_test_open_font_file ("fonts/adwaita.ttf");
+  font = hb_font_create (face);
+
+  ret = hb_font_get_glyph_name (font, 0, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, ".notdef");
+
+  ret = hb_font_get_glyph_name (font, 1, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, ".space");
+
+  ret = hb_font_get_glyph_name (font, 2, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, "icon0");
+
+  ret = hb_font_get_glyph_name (font, 3, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, "icon0.0");
+
+  ret = hb_font_get_glyph_name (font, 4, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, "icon0.1");
+
+  ret = hb_font_get_glyph_name (font, 5, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, "icon0.2");
+
+  /* beyond last glyph */
+  ret = hb_font_get_glyph_name (font, 100, name, 64);
+  g_assert_false (ret);
+
+  hb_font_destroy (font);
+  hb_face_destroy (face);
+}
+
+static void
+test_glyph_names_cff (void)
+{
+  hb_face_t *face;
+  hb_font_t *font;
+  hb_bool_t ret;
+  char name [64];
+
+  face = hb_test_open_font_file ("fonts/SourceSansPro-Regular.otf");
+  font = hb_font_create (face);
+
+  ret = hb_font_get_glyph_name (font, 0, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, ".notdef");
+
+  ret = hb_font_get_glyph_name (font, 1, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, "space");
+
+  ret = hb_font_get_glyph_name (font, 2, name, 64);
+  g_assert_true (ret);
+  g_assert_cmpstr (name, ==, "A");
+
+  /* beyond last glyph */
+  ret = hb_font_get_glyph_name (font, 2000, name, 64);
+  g_assert_false (ret);
+
+  hb_font_destroy (font);
+  hb_face_destroy (face);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+
+  hb_test_add (test_glyph_names_post);
+  hb_test_add (test_glyph_names_cff);
+
+  return hb_test_run();
+}