test: Add a test for characters in the SMP

Unicode characters in the Supplementary Multilingual Plane are encoded
as surrogate pairs in UTF-16. This test tries to verify that backends
do not perform UCS4 to UTF-16 conversion by truncation.

test/Makefile.sources

@@ -323,6 +323,7 @@ test_sources = \
 	smask-paint.c					\
 	smask-stroke.c					\
 	smask-text.c					\
+	smp-glyph.c					\
 	solid-pattern-cache-stress.c			\
 	source-clip.c					\
 	source-clip-scale.c				\

test/smp-glyph.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright © 2017 Andrea Canciani
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Andrea Canciani not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Andrea Canciani makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * ANDREA CANCIANI DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL ANDREA CANCIANI BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Andrea Canciani <ranma42@gmail.com>
+ */
+
+#include "cairo-test.h"
+
+#define TEXT_SIZE 42
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
+    cairo_paint (cr);
+
+    cairo_set_source_rgb (cr, 0, 0, 0); /* black */
+
+    cairo_select_font_face (cr, CAIRO_TEST_FONT_FAMILY " Sans",
+			    CAIRO_FONT_SLANT_NORMAL,
+			    CAIRO_FONT_WEIGHT_NORMAL);
+
+    cairo_set_font_size (cr, TEXT_SIZE);
+    cairo_translate (cr, 0, TEXT_SIZE);
+
+    /* U+1F030, DOMINO TILE HORIZONTAL BACK */
+    cairo_show_text (cr, "\xf0\x9f\x80\xb0");
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (smp_glyph,
+	    "Test glyphs for symbols in the Supplementary Multilingual Plane",
+	    "text, glyphs", /* keywords */
+	    NULL, /* requirements */
+	    64, 64,
+	    NULL, draw)