3 files changed, 83 insertions, 3 deletions

diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index bc8d5a3577..38bc187f4f 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -1093,7 +1093,7 @@ static int nlua_rpc(lua_State *lstate, bool request)
     Object result = rpc_send_call(chan_id, name, args, &res_mem, &err);
     if (!ERROR_SET(&err)) {
       nlua_push_Object(lstate, result, false);
-      arena_mem_free(res_mem, NULL);
+      arena_mem_free(res_mem);
     }
   } else {
     if (!rpc_send_event(chan_id, name, args)) {
@@ -1662,6 +1662,9 @@ static void nlua_add_treesitter(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL
   lua_pushcfunction(lstate, tslua_has_language);
   lua_setfield(lstate, -2, "_ts_has_language");
 
+  lua_pushcfunction(lstate, tslua_remove_lang);
+  lua_setfield(lstate, -2, "_ts_remove_language");
+
   lua_pushcfunction(lstate, tslua_inspect_lang);
   lua_setfield(lstate, -2, "_ts_inspect_language");
 
diff --git a/src/nvim/lua/stdlib.c b/src/nvim/lua/stdlib.c
index 5a82ae30b5..64e9abe0c9 100644
--- a/src/nvim/lua/stdlib.c
+++ b/src/nvim/lua/stdlib.c
@@ -474,6 +474,52 @@ static int nlua_stricmp(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL
   return 1;
 }
 
+#if defined(HAVE_ICONV)
+
+/// Convert string from one encoding to another
+static int nlua_iconv(lua_State *lstate)
+{
+  int narg = lua_gettop(lstate);
+
+  if (narg < 3) {
+    return luaL_error(lstate, "Expected at least 3 arguments");
+  }
+
+  for (int i = 1; i <= 3; i++) {
+    if (lua_type(lstate, i) != LUA_TSTRING) {
+      return luaL_argerror(lstate, i, "expected string");
+    }
+  }
+
+  size_t str_len = 0;
+  const char *str = lua_tolstring(lstate, 1, &str_len);
+
+  char_u *from = enc_canonize(enc_skip((char_u *)lua_tolstring(lstate, 2, NULL)));
+  char_u *to   = enc_canonize(enc_skip((char_u *)lua_tolstring(lstate, 3, NULL)));
+
+  vimconv_T vimconv;
+  vimconv.vc_type = CONV_NONE;
+  convert_setup_ext(&vimconv, from, false, to, false);
+
+  char_u *ret = string_convert(&vimconv, (char_u *)str, &str_len);
+
+  convert_setup(&vimconv, NULL, NULL);
+
+  xfree(from);
+  xfree(to);
+
+  if (ret == NULL) {
+    lua_pushnil(lstate);
+  } else {
+    lua_pushlstring(lstate, (char *)ret, str_len);
+    xfree(ret);
+  }
+
+  return 1;
+}
+
+#endif
+
 void nlua_state_add_stdlib(lua_State *const lstate, bool is_thread)
 {
   if (!is_thread) {
@@ -519,6 +565,13 @@ void nlua_state_add_stdlib(lua_State *const lstate, bool is_thread)
     // vim.spell
     luaopen_spell(lstate);
     lua_setfield(lstate, -2, "spell");
+
+#if defined(HAVE_ICONV)
+    // vim.iconv
+    // depends on p_ambw, p_emoji
+    lua_pushcfunction(lstate, &nlua_iconv);
+    lua_setfield(lstate, -2, "iconv");
+#endif
   }
 
   // vim.mpack
diff --git a/src/nvim/lua/treesitter.c b/src/nvim/lua/treesitter.c
index f0d847e352..8b47939169 100644
--- a/src/nvim/lua/treesitter.c
+++ b/src/nvim/lua/treesitter.c
@@ -14,11 +14,14 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
+#include <uv.h>
 
 #include "nvim/api/private/helpers.h"
 #include "nvim/buffer.h"
 #include "nvim/lib/kvec.h"
+#include "nvim/log.h"
 #include "nvim/lua/treesitter.h"
+#include "nvim/map.h"
 #include "nvim/memline.h"
 #include "tree_sitter/api.h"
 
@@ -145,18 +148,27 @@ int tslua_has_language(lua_State *L)
   return 1;
 }
 
+// Creates the language into the internal language map.
+//
+// Returns true if the language is correctly loaded in the language map
 int tslua_add_language(lua_State *L)
 {
   const char *path = luaL_checkstring(L, 1);
   const char *lang_name = luaL_checkstring(L, 2);
+  const char *symbol_name = lang_name;
+
+  if (lua_gettop(L) >= 3 && !lua_isnil(L, 3)) {
+    symbol_name = luaL_checkstring(L, 3);
+  }
 
   if (pmap_has(cstr_t)(&langs, lang_name)) {
-    return 0;
+    lua_pushboolean(L, true);
+    return 1;
   }
 
 #define BUFSIZE 128
   char symbol_buf[BUFSIZE];
-  snprintf(symbol_buf, BUFSIZE, "tree_sitter_%s", lang_name);
+  snprintf(symbol_buf, BUFSIZE, "tree_sitter_%s", symbol_name);
 #undef BUFSIZE
 
   uv_lib_t lib;
@@ -179,6 +191,7 @@ int tslua_add_language(lua_State *L)
 
   TSLanguage *lang = lang_parser();
   if (lang == NULL) {
+    uv_dlclose(&lib);
     return luaL_error(L, "Failed to load parser %s: internal error", path);
   }
 
@@ -198,6 +211,17 @@ int tslua_add_language(lua_State *L)
   return 1;
 }
 
+int tslua_remove_lang(lua_State *L)
+{
+  const char *lang_name = luaL_checkstring(L, 1);
+  bool present = pmap_has(cstr_t)(&langs, lang_name);
+  if (present) {
+    pmap_del(cstr_t)(&langs, lang_name);
+  }
+  lua_pushboolean(L, present);
+  return 1;
+}
+
 int tslua_inspect_lang(lua_State *L)
 {
   const char *lang_name = luaL_checkstring(L, 1);