str_buf_cat(): should allocate at least RSTRING_EMBED_LEN_MAX+1.

mruby · Dec 31, 2016 · 342b1de · 342b1de
1 parent cfdd1e3
commit 342b1de
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/src/string.c b/src/string.c
@@ -158,6 +158,8 @@ str_buf_cat(mrb_state *mrb, struct RString *s, const char *ptr, size_t len)
     capa = RSTRING_EMBED_LEN_MAX;
   else
     capa = s->as.heap.aux.capa;
+  if (capa <= RSTRING_EMBED_LEN_MAX)
+    capa = RSTRING_EMBED_LEN_MAX+1;
 
   total = RSTR_LEN(s)+len;
   if (total >= MRB_INT_MAX) {