[pacman-dev] [PATCH] Fix segfault during install when a package update adds a new file to 'backup'

[Will Miles]

When a new package release adds a new entry to the backup list, no hash exists
for that file in the previously installed package version.  Fix two places
where that nonexistent hash may be dereferenced.

Signed-off-by: Will Miles <wmiles at sgl.com>
---
 lib/libalpm/add.c      | 2 +-
 lib/libalpm/be_local.c | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
index f5c9a95..ff0b81d 100644
--- a/lib/libalpm/add.c
+++ b/lib/libalpm/add.c
@@ -341,7 +341,7 @@ static int extract_single_file(alpm_handle_t *handle, struct archive *archive,
 		_alpm_log(handle, ALPM_LOG_DEBUG, "checking hashes for %s\n", origfile);
 		_alpm_log(handle, ALPM_LOG_DEBUG, "current:  %s\n", hash_local);
 		_alpm_log(handle, ALPM_LOG_DEBUG, "new:      %s\n", hash_pkg);
-		_alpm_log(handle, ALPM_LOG_DEBUG, "original: %s\n", hash_orig);
+		_alpm_log(handle, ALPM_LOG_DEBUG, "original: %s\n", (hash_orig ? hash_orig : "NULL") );
 
 		if(hash_local && hash_pkg && strcmp(hash_local, hash_pkg) == 0) {
 			/* local and new files are the same, updating anyway to get
diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
index f817822..5e39199 100644
--- a/lib/libalpm/be_local.c
+++ b/lib/libalpm/be_local.c
@@ -1037,7 +1037,9 @@ int _alpm_local_db_write(alpm_db_t *db, alpm_pkg_t *info, alpm_dbinfrq_t inforeq
 			fputs("%BACKUP%\n", fp);
 			for(lp = info->backup; lp; lp = lp->next) {
 				const alpm_backup_t *backup = lp->data;
-				fprintf(fp, "%s\t%s\n", backup->name, backup->hash);
+				if (backup->hash) {
+					fprintf(fp, "%s\t%s\n", backup->name, backup->hash);
+				}
 			}
 			fputc('\n', fp);
 		}
-- 
2.6.3