be_sync: use effective URL for db file signature download

If download server is dynamic mirror chances are that db file download
and db file signature download are redirected to different mirrors,
resulting in invalid signature.
This uses effective URL for db file signature download and makes the
files always match.

Signed-off-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Allan McRae <allan@archlinux.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index b03d273a..6572a8ad 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -209,6 +209,7 @@ int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 	}
 
 	for(i = db->servers; i; i = i->next) {
+		char *final_db_url = NULL;
 		const char *server = i->data;
 		struct dload_payload payload;
 		size_t len;
@@ -228,7 +229,7 @@ int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 		payload.force = force;
 		payload.unlink_on_fail = 1;
 
-		ret = _alpm_download(&payload, syncpath, NULL, NULL);
+		ret = _alpm_download(&payload, syncpath, NULL, &final_db_url);
 		_alpm_dload_payload_reset(&payload);
 
 		if(ret == 0 && (level & ALPM_SIG_DATABASE)) {
@@ -242,11 +243,11 @@ int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 			free(sigpath);
 
 			/* if we downloaded a DB, we want the .sig from the same server */
-			/* print server + filename into a buffer (leave space for .sig) */
-			len = strlen(server) + strlen(db->treename) + 9;
+			/* print final_db_url into a buffer (leave space for .sig) */
+			len = strlen(final_db_url) + 5;
 			/* TODO fix leak syncpath and umask unset */
 			MALLOC(payload.fileurl, len, RET_ERR(handle, ALPM_ERR_MEMORY, -1));
-			snprintf(payload.fileurl, len, "%s/%s.db.sig", server, db->treename);
+			snprintf(payload.fileurl, len, "%s.sig", final_db_url);
 			payload.handle = handle;
 			payload.force = 1;
 			payload.errors_ok = (level & ALPM_SIG_DATABASE_OPTIONAL);