Maintain list tail pointers in the head node

List head nodes contain null 'prev' pointer, which we can (ab)use to maintain a
back reference to the tail pointer of the list.

While list additions are not _significantly_ improved, they are still sped up.

Original
   $ time pacman -Qo /usr/bin/wtpt
   /usr/bin/wtpt is owned by lcms 1.17-2

   real    0m3.623s
   user    0m1.883s
   sys     0m1.473s

New
   $ time pacman -Qo /usr/bin/wtpt
   /usr/bin/wtpt is owned by lcms 1.17-2

   real    0m2.006s
   user    0m0.263s
   sys     0m1.627s

Signed-off-by: Aaron Griffin <aaronmgriffin@gmail.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/libalpm/remove.c b/lib/libalpm/remove.c
index 6bbb4655..a4c3c15c 100644
--- a/lib/libalpm/remove.c
+++ b/lib/libalpm/remove.c
@@ -304,7 +304,8 @@ int _alpm_remove_commit(pmtrans_t *trans, pmdb_t *db)
 			_alpm_log(PM_LOG_DEBUG, "removing %d files\n", filenum);
 
 			/* iterate through the list backwards, unlinking files */
-			for(lp = alpm_list_last(files); lp; lp = lp->prev) {
+			files = alpm_list_reverse(files);
+			for(lp = files; lp; lp = alpm_list_next(lp)) {
 				unlink_file(info, lp, trans);
 
 				/* update progress bar after each file */