fix encode bug.

README.md

@@ -34,7 +34,7 @@ in your codes :-(
 
 LuaRocks Installation
 ---------------------
-`luarocks install utf8`
+`luarocks install luautf8`
 
 It's now full-compatible with Lua5.3's utf8 library, so replace this
 file (and headers) with lua5.3 source's lutf8lib.c is also okay.

lutf8lib.c

@@ -33,9 +33,9 @@ static size_t utf8_encode(char *s, unsigned ch) {
   {
     char buff[UTF8_MAX];
     unsigned mfb = 0x3F; /* maximum that fits in first byte */
-    int n = 0;
+    int n = 1;
     do { /* add continuation bytes */
-      buff[UTF8_MAX - (++n)] = 0x80 | (ch&0x3F);
+      buff[UTF8_MAX - (n++)] = 0x80 | (ch&0x3F);
       ch >>= 6; /* remove added bits */
       mfb >>= 1; /* now there is one less bit available in first byte */
     } while (ch > mfb);  /* still needs continuation byte? */

rockspecs/luautf8-0.1.1-1.rockspec

@@ -0,0 +1,23 @@
+package = "luautf8"
+version = "0.1.1-1"
+source = {
+   url = "https://github.com/starwing/luautf8/archive/0.1.1.tar.gz",
+   dir = "luautf8-0.1.1"
+}
+description = {
+   summary = "A UTF-8 support module for Lua",
+   detailed = [[
+   This module adds UTF-8 support to Lua. It's compatible with Lua "string" module.
+  ]],
+   homepage = "http://github.com/starwing/luautf8",
+   license = "MIT"
+}
+dependencies = {
+   "lua >= 5.1"
+}
+build = {
+   type = "builtin",
+   modules = {
+      ["lua-utf8"] = "lutf8lib.c"
+   }
+}