From: Ben Pfaff <blp@cs.stanford.edu>
Date: Fri, 19 Apr 2024 00:27:12 +0000 (-0700)
Subject: transformations: Fix memory error in trns_chain_prepend().
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1b8d98ec1db4dc7884231db16ea771f2d293893f;p=pspp

transformations: Fix memory error in trns_chain_prepend().

This only worked if the transformation chain had one element.

Thanks to Zhou Geng for reporting this bug as poc30 in the report here:
https://lists.gnu.org/archive/html/bug-gnu-pspp/2024-03/msg00015.html
---

diff --git a/src/data/transformations.c b/src/data/transformations.c
index fdb2cb84bd..55067ea878 100644
--- a/src/data/transformations.c
+++ b/src/data/transformations.c
@@ -61,7 +61,7 @@ trns_chain_prepend (struct trns_chain *chain, const struct transformation *t)
     chain->xforms = x2nrealloc (chain->xforms, &chain->allocated,
                                 sizeof *chain->xforms);
 
-  insert_element (chain->xforms, 1, sizeof *chain->xforms, 0);
+  insert_element (chain->xforms, chain->n, sizeof *chain->xforms, 0);
   chain->xforms[0] = *t;
   chain->n++;
 }