2 files changed, 20 insertions, 0 deletions
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index c35e0b2ada..1468c5564e 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -1716,6 +1716,8 @@ static void f_exists(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     } else {
       n = au_exists(p + 1);
     }
+  } else if (strncmp(p, "v:lua.", 6) == 0 && nlua_func_exists(p + 6)) {
+    n = true;
   } else {  // Internal variable.
     n = var_exists(p);
   }
diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index e665732c1a..e0bdbbc1e9 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -2313,3 +2313,21 @@ void nlua_init_defaults(void)
     os_errmsg("\n");
   }
 }
+
+/// check lua function exist
+bool nlua_func_exists(const char *lua_funcname)
+{
+  MAXSIZE_TEMP_ARRAY(args, 1);
+  size_t length = strlen(lua_funcname) + 8;
+  char *str = xmalloc(length);
+  vim_snprintf(str, length, "return %s", lua_funcname);
+  ADD_C(args, CSTR_AS_OBJ(str));
+  Error err = ERROR_INIT;
+  Object result = NLUA_EXEC_STATIC("return type(loadstring(...)()) =='function'", args, &err);
+  xfree(str);
+
+  if (result.type != kObjectTypeBoolean) {
+    return false;
+  }
+  return result.data.boolean;
+}