Improve jid.split() and jid.bare() to pass new test cases with invalid JIDs

tests/test_util_jid.lua

@@ -11,4 +11,24 @@ function split(split)
 	test("server", 			nil, 	"server", nil		);
 	test("server/resource", 	nil, 	"server", "resource"	);
 	test(nil,			nil,	nil	, nil		);
+
+	test("node@/server", nil, nil, nil , nil );
+end
+
+function bare(bare)
+	assert_equal(bare("user@host"), "user@host", "bare JID remains bare");
+	assert_equal(bare("host"), "host", "Host JID remains host");
+	assert_equal(bare("host/resource"), "host", "Host JID with resource becomes host");
+	assert_equal(bare("user@host/resource"), "user@host", "user@host JID with resource becomes user@host");
+	assert_equal(bare("user@/resource"), nil, "invalid JID is nil");
+	assert_equal(bare("@/resource"), nil, "invalid JID is nil");
+	assert_equal(bare("@/"), nil, "invalid JID is nil");
+	assert_equal(bare("/"), nil, "invalid JID is nil");
+	assert_equal(bare(""), nil, "invalid JID is nil");
+	assert_equal(bare("@"), nil, "invalid JID is nil");
+	assert_equal(bare("user@"), nil, "invalid JID is nil");
+	assert_equal(bare("user@@"), nil, "invalid JID is nil");
+	assert_equal(bare("user@@host"), nil, "invalid JID is nil");
+	assert_equal(bare("user@@host/resource"), nil, "invalid JID is nil");
+	assert_equal(bare("user@host/"), nil, "invalid JID is nil");
 end

util/jid.lua

@@ -1,20 +1,28 @@
 
 local match = string.match;
-
+local tostring = tostring;
+local print = print
 module "jid"
 
 function split(jid)
 	if not jid then return; end
 	-- TODO verify JID, and return; if invalid
-	local node = match(jid, "^([^@]+)@");
-	local server = (node and match(jid, ".-@([^@/]+)")) or match(jid, "^([^@/]+)");
-	local resource = match(jid, "/(.+)$");
-	return node, server, resource;
+	local node, nodelen = match(jid, "^([^@]+)@()");
+	local host, hostlen = match(jid, "^([^@/]+)()", nodelen)
+	if node and not host then return nil, nil, nil; end
+	local resource = match(jid, "^/(.+)$", hostlen);
+	if (not host) or ((not resource) and #jid >= hostlen) then return nil, nil, nil; end
+	return node, host, resource;
 end
 
 function bare(jid)
 	local node, host = split(jid);
-	return node.."@"..host;
+	if node and host then
+		return node.."@"..host;
+	elseif host then
+		return host;
+	end
+	return nil;
 end
 
-return _M;
+return _M;