From: Friedrich Beckmann <friedrich.beckmann@gmx.de>
Date: Sun, 28 Jun 2020 19:51:09 +0000 (+0200)
Subject: trim.c: avoid zero size xnrealloc memory allocation
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e2039bc0694b89d26065899d9ed20f9bb42426f4;p=pspp

trim.c: avoid zero size xnrealloc memory allocation

Without the patch the regression fails on test

GET with /KEEP=ALL crashes -- uncompressed

when I compile with -fsanitize=address on MacOS. The reason
is that xnrealloc is called with a zero size allocation. I
simply avoid this, although it might be perfectly o.k. to do so.
---

diff --git a/src/language/data-io/trim.c b/src/language/data-io/trim.c
index 2ef085e796..00ebcbbe67 100644
--- a/src/language/data-io/trim.c
+++ b/src/language/data-io/trim.c
@@ -302,6 +302,8 @@ parse_dict_keep (struct lexer *lexer, struct dictionary *dict)
   dict_reorder_vars (dict, v, nv);
 
   /* Delete the remaining variables. */
+  if (dict_get_var_cnt (dict) == nv)
+    return true;
   v = xnrealloc (v, dict_get_var_cnt (dict) - nv, sizeof *v);
   for (i = nv; i < dict_get_var_cnt (dict); i++)
     v[i - nv] = dict_get_var (dict, i);