fix: terminate XIM UTF-8 text runs

tests/xim_test.c

@@ -32,6 +32,26 @@ checktext(const char *s)
 	free(ct);
 }
 
+static void
+checkfallback(void)
+{
+	static const char s[] = "😀";
+	static const char want[] = "\033%G😀\033%@";
+	char *ct, *utf8;
+	size_t clen, ulen;
+
+	ct = ximutf8compound(s, sizeof s - 1, &clen);
+	assert(ct != NULL);
+	assert(clen == sizeof want - 1);
+	assert(memcmp(ct, want, clen) == 0);
+	utf8 = xcb_compound_text_to_utf8(ct, clen, &ulen);
+	assert(utf8 != NULL);
+	assert(ulen == sizeof s - 1);
+	assert(memcmp(utf8, s, ulen) == 0);
+	free(utf8);
+	free(ct);
+}
+
 int
 main(void)
 {
@@ -61,5 +81,6 @@ main(void)
 	checktext("😀");
 	checktext("❤️");
 	checktext("A😀한");
+	checkfallback();
 	return 0;
 }