1 files changed, 9 insertions, 4 deletions

diff --git a/src/lj_meta.c b/src/lj_meta.c
index 07defa55..660dfec0 100644
--- a/src/lj_meta.c
+++ b/src/lj_meta.c
@@ -240,8 +240,8 @@ TValue *lj_meta_cat(lua_State *L, TValue *top, int left)
   int fromc = 0;
   if (left < 0) { left = -left; fromc = 1; }
   do {
-    if (!(tvisstr(top) || tvisnumber(top)) ||
-        !(tvisstr(top-1) || tvisnumber(top-1))) {
+    if (!(tvisstr(top) || tvisnumber(top) || tvisbuf(top)) ||
+        !(tvisstr(top-1) || tvisnumber(top-1) || tvisbuf(top-1))) {
       cTValue *mo = lj_meta_lookup(L, top-1, MM_concat);
       if (tvisnil(mo)) {
         mo = lj_meta_lookup(L, top, MM_concat);
@@ -277,10 +277,12 @@ TValue *lj_meta_cat(lua_State *L, TValue *top, int left)
       ** next step: [...][CAT stack ............]
       */
       TValue *e, *o = top;
-      uint64_t tlen = tvisstr(o) ? strV(o)->len : STRFMT_MAXBUF_NUM;
+      uint64_t tlen = tvisstr(o) ? strV(o)->len :
+                      tvisbuf(o) ? sbufxlen(bufV(o)) : STRFMT_MAXBUF_NUM;
       SBuf *sb;
       do {
-        o--; tlen += tvisstr(o) ? strV(o)->len : STRFMT_MAXBUF_NUM;
+        o--; tlen += tvisstr(o) ? strV(o)->len :
+                     tvisbuf(o) ? sbufxlen(bufV(o)) : STRFMT_MAXBUF_NUM;
       } while (--left > 0 && (tvisstr(o-1) || tvisnumber(o-1)));
       if (tlen >= LJ_MAX_STR) lj_err_msg(L, LJ_ERR_STROV);
       sb = lj_buf_tmp_(L);
@@ -290,6 +292,9 @@ TValue *lj_meta_cat(lua_State *L, TValue *top, int left)
           GCstr *s = strV(o);
           MSize len = s->len;
           lj_buf_putmem(sb, strdata(s), len);
+        } else if (tvisbuf(o)) {
+          SBufExt *sbx = bufV(o);
+          lj_buf_putmem(sb, sbx->r, sbufxlen(sbx));
         } else if (tvisint(o)) {
           lj_strfmt_putint(sb, intV(o));
         } else {