add a test for the utf8 option

src/tests/encoding.vtc

+# looks like -*- vcl -*-
+
+varnishtest "latin1 and utf8 encoding"
+
+# Tests from re2 testing/re2_test.cc
+varnish v1 -vcl {
+	import re2 from "${vmod_topbuild}/src/.libs/libvmod_re2.so";
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+	       new ninebytes = re2.regex("^.........$");
+	       new threechars = re2.regex("^...$", utf8=true);
+	       new capture_one_byte = re2.regex("(.)");
+	       new capture_one_char = re2.regex("(.)", utf8=true);
+	       new bytes = re2.regex({"^日扼語$"});
+	       new chars = re2.regex({"^日扼語$"}, utf8=true);
+	       new patternbytes = re2.regex({"^.扼.$"});
+	       new patternchars = re2.regex({"^.扼.$"}, utf8=true);
+	}
+
+	sub vcl_recv {
+		return(synth(200));
+	}
+
+	sub vcl_synth {
+		if (ninebytes.match({"日扼語"})) {
+			set resp.http.ninebytes = "match";
+		}
+		if (threechars.match({"日扼語"})) {
+			set resp.http.threechars = "match";
+		}
+		if (capture_one_byte.match({"日扼語"})) {
+			if (capture_one_byte.backref(1) == {""}) {
+				set resp.http.captured_one_byte = "true";
+			}
+		}
+		if (capture_one_char.match({"日扼語"})) {
+			if (capture_one_char.backref(1) == {"日"}) {
+				set resp.http.captured_one_char = "true";
+			}
+		}
+		if (bytes.match({"日扼語"})) {
+			set resp.http.bytes = "match";
+		}
+		if (chars.match({"日扼語"})) {
+			set resp.http.chars = "match";
+		}
+		if (patternbytes.match({"日扼語"})) {
+			set resp.http.patternbytes = "match";
+		}
+		if (patternchars.match({"日扼語"})) {
+			set resp.http.patternchars = "match";
+		}
+	}
+
+} -start
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.http.ninebytes == "match"
+	expect resp.http.threechars == "match"
+	expect resp.http.captured_one_byte == "true"
+	expect resp.http.captured_one_char == "true"
+	expect resp.http.bytes == "match"
+	expect resp.http.chars == "match"
+	expect resp.http.patternbytes == <undef>
+	expect resp.http.patternchars == "match"
+} -run