4 files changed, 19 insertions, 7 deletions

diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index e46942d9..5285ac39 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -397,7 +397,7 @@ alpm_list_t * alpm_trans_get_pkgs();
 int alpm_trans_init(pmtranstype_t type, pmtransflag_t flags,
                     alpm_trans_cb_event cb_event, alpm_trans_cb_conv conv,
                     alpm_trans_cb_progress cb_progress);
-int alpm_trans_sysupgrade(void);
+int alpm_trans_sysupgrade(int enable_downgrade);
 int alpm_trans_addtarget(char *target);
 int alpm_trans_prepare(alpm_list_t **data);
 int alpm_trans_commit(alpm_list_t **data);
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index ffcddf98..47639248 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -80,7 +80,7 @@ pmpkg_t SYMEXPORT *alpm_sync_newversion(pmpkg_t *pkg, alpm_list_t *dbs_sync)
 	return(NULL);
 }
 
-int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync)
+int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, int enable_downgrade)
 {
 	alpm_list_t *i, *j, *k;
 
@@ -116,8 +116,20 @@ int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_s
 						trans->packages = alpm_list_add(trans->packages, spkg);
 					}
 				} else if(cmp < 0) {
-					_alpm_log(PM_LOG_WARNING, _("%s: local (%s) is newer than %s (%s)\n"),
-							lpkg->name, lpkg->version, sdb->treename, spkg->version);
+					if(enable_downgrade) {
+						/* check IgnorePkg/IgnoreGroup */
+						if(_alpm_pkg_should_ignore(spkg) || _alpm_pkg_should_ignore(lpkg)) {
+							_alpm_log(PM_LOG_WARNING, _("%s: ignoring package downgrade (%s => %s)\n"),
+											lpkg->name, lpkg->version, spkg->version);
+						} else {
+							_alpm_log(PM_LOG_WARNING, _("%s: downgrading from version %s to version %s\n"),
+											lpkg->name, lpkg->version, spkg->version);
+							trans->packages = alpm_list_add(trans->packages, spkg);
+						}
+					} else {
+						_alpm_log(PM_LOG_WARNING, _("%s: local (%s) is newer than %s (%s)\n"),
+								lpkg->name, lpkg->version, sdb->treename, spkg->version);
+					}
 				}
 				break; /* jump to next local package */
 			} else { /* 2. search for replacers in sdb */
diff --git a/lib/libalpm/sync.h b/lib/libalpm/sync.h
index 5d642073..c2905a45 100644
--- a/lib/libalpm/sync.h
+++ b/lib/libalpm/sync.h
@@ -24,7 +24,7 @@
 
 #include "alpm.h"
 
-int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync);
+int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, int enable_downgrade);
 
 int _alpm_sync_addtarget(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, char *name);
 int _alpm_sync_prepare(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, alpm_list_t **data);
diff --git a/lib/libalpm/trans.c b/lib/libalpm/trans.c
index d1c0e930..6e847e64 100644
--- a/lib/libalpm/trans.c
+++ b/lib/libalpm/trans.c
@@ -89,7 +89,7 @@ int SYMEXPORT alpm_trans_init(pmtranstype_t type, pmtransflag_t flags,
 /** Search for packages to upgrade and add them to the transaction.
  * @return 0 on success, -1 on error (pm_errno is set accordingly)
  */
-int SYMEXPORT alpm_trans_sysupgrade()
+int SYMEXPORT alpm_trans_sysupgrade(int enable_downgrade)
 {
 	pmtrans_t *trans;
 
@@ -102,7 +102,7 @@ int SYMEXPORT alpm_trans_sysupgrade()
 	ASSERT(trans->state == STATE_INITIALIZED, RET_ERR(PM_ERR_TRANS_NOT_INITIALIZED, -1));
 	ASSERT(trans->type == PM_TRANS_TYPE_SYNC, RET_ERR(PM_ERR_TRANS_TYPE, -1));
 
-	return(_alpm_sync_sysupgrade(trans, handle->db_local, handle->dbs_sync));
+	return(_alpm_sync_sysupgrade(trans, handle->db_local, handle->dbs_sync, enable_downgrade));
 }
 
 /** Add a target to the transaction.