Fix a possible segfault in alpm/remove.c

Before removing a package from target list (in remove_prepare_keep_needed),
we should check whether we have already removed it.

Signed-off-by: Nagy Gabor <ngaba@bibl.u-szeged.hu>
Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/libalpm/remove.c b/lib/libalpm/remove.c
index 625abe67..864fafaf 100644
--- a/lib/libalpm/remove.c
+++ b/lib/libalpm/remove.c
@@ -120,6 +120,9 @@ static void remove_prepare_keep_needed(pmtrans_t *trans, pmdb_t *db,
 			pmdepmissing_t *miss = (pmdepmissing_t *)i->data;
 			void *vpkg;
 			pmpkg_t *pkg = _alpm_pkg_find(trans->packages, miss->causingpkg);
+			if(pkg == NULL) {
+				continue;
+			}
 			trans->packages = alpm_list_remove(trans->packages, pkg, _alpm_pkg_cmp,
 					&vpkg);
 			pkg = vpkg;