From eaf661dacd74b098de768ddc459ae2e68bb6d668 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Linse?= <bjorn.linse@gmail.com>
Date: Sat, 4 Sep 2021 17:16:51 +0200
Subject: [PATCH] feat(lua): add vim.mpack for msgpack support in lua

---
 src/mpack/lmpack.c      |  6 ++++++
 src/nvim/lua/executor.c | 16 ++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/src/mpack/lmpack.c b/src/mpack/lmpack.c
index 9f102fc950..a66caf20ca 100644
--- a/src/mpack/lmpack.c
+++ b/src/mpack/lmpack.c
@@ -1139,16 +1139,19 @@ int luaopen_mpack(lua_State *L)
   lua_pushvalue(L, -1);
   lua_setfield(L, -2, "__index");
   luaL_register(L, NULL, unpacker_methods);
+  lua_pop(L, 1);
   /* Packer */
   luaL_newmetatable(L, PACKER_META_NAME);
   lua_pushvalue(L, -1);
   lua_setfield(L, -2, "__index");
   luaL_register(L, NULL, packer_methods);
+  lua_pop(L, 1);
   /* Session */
   luaL_newmetatable(L, SESSION_META_NAME);
   lua_pushvalue(L, -1);
   lua_setfield(L, -2, "__index");
   luaL_register(L, NULL, session_methods);
+  lua_pop(L, 1);
   /* NIL */
   /* Check if NIL is already stored in the registry */
   lua_getfield(L, LUA_REGISTRYINDEX, NIL_NAME);
@@ -1166,6 +1169,9 @@ int luaopen_mpack(lua_State *L)
     /* Save NIL on the registry so we can access it easily from other functions */
     lua_setfield(L, LUA_REGISTRYINDEX, NIL_NAME);
   }
+
+  lua_pop(L, 1);
+
   /* module */
   lua_newtable(L);
   luaL_register(L, NULL, mpack_functions);
diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index a8b10f86f5..2facfa28cd 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -33,6 +33,7 @@
 #include "nvim/eval/userfunc.h"
 #include "nvim/event/time.h"
 #include "nvim/event/loop.h"
+#include "mpack/lmpack.h"
 
 #include "nvim/os/os.h"
 
@@ -508,6 +509,21 @@ static int nlua_state_init(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL
   nlua_nil_ref = nlua_ref(lstate, -1);
   lua_setfield(lstate, -2, "NIL");
 
+
+  // vim.mpack
+  luaopen_mpack(lstate);
+  lua_pushvalue(lstate, -1);
+  lua_setfield(lstate, -3, "mpack");
+
+  // package.loaded.mpack = vim.mpack
+  // otherwise luv will be reinitialized when require'mpack'
+  lua_getglobal(lstate, "package");
+  lua_getfield(lstate, -1, "loaded");
+  lua_pushvalue(lstate, -3);
+  lua_setfield(lstate, -2, "mpack");
+  lua_pop(lstate, 3);
+
+
   // vim._empty_dict_mt
   lua_createtable(lstate, 0, 0);
   lua_pushcfunction(lstate, &nlua_empty_dict_tostring);