xalloc: delay setting size until success

* lib/xalloc.h (x2nrealloc): Don’t change *PN until after xrealloc
succeeds, in case xalloc_die or one of its callees or longjmp
targets uses *PN.  Similar code in xpalloc already does this.

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/xalloc.h b/lib/xalloc.h
index 76d83c63c1..5633fdf3c4 100644
--- a/lib/xalloc.h
+++ b/lib/xalloc.h
@@ -206,8 +206,9 @@ x2nrealloc (void *p, size_t *pn, size_t s)
       n += n / 2 + 1;
     }
 
+  p = xrealloc (p, n * s);
   *pn = n;
-  return xrealloc (p, n * s);
+  return p;
 }
 
 /* Return a pointer to a new buffer of N bytes.  This is like xmalloc,