From f0e865dd4861520258299d0f2a56491bd9d602e1 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Thu, 10 Jan 2019 13:09:17 +0100
Subject: [PATCH 59/72] Improve luaL_addlstring().

Thanks to Domingo Alvarez Duarte.
---
 src/lib_aux.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/lib_aux.c b/src/lib_aux.c
index c40565c..2682a38 100644
--- a/src/lib_aux.c
+++ b/src/lib_aux.c
@@ -218,8 +218,15 @@ LUALIB_API char *luaL_prepbuffer(luaL_Buffer *B)
 
 LUALIB_API void luaL_addlstring(luaL_Buffer *B, const char *s, size_t l)
 {
-  while (l--)
-    luaL_addchar(B, *s++);
+  if (l <= bufffree(B)) {
+    memcpy(B->p, s, l);
+    B->p += l;
+  } else {
+    emptybuffer(B);
+    lua_pushlstring(B->L, s, l);
+    B->lvl++;
+    adjuststack(B);
+  }
 }
 
 LUALIB_API void luaL_addstring(luaL_Buffer *B, const char *s)
-- 
2.20.1