Check local DB version before continuing transaction

Ensure we have a local DB version that is up to par with what we expect
before we go down any road that might modify it. This should prevent
stupid mistakes with the 3.5.X upgrade and people not running
pacman-db-upgrade after the transaction as they will need to.

Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
index c1e86a63..848ecc58 100644
--- a/lib/libalpm/be_local.c
+++ b/lib/libalpm/be_local.c
@@ -924,9 +924,62 @@ int _alpm_local_db_remove(pmdb_t *db, pmpkg_t *info)
 	return(ret);
 }
 
+static int local_db_version(pmdb_t *db)
+{
+	struct dirent *ent = NULL;
+	const char *dbpath;
+	DIR *dbdir;
+	int version;
+
+	dbpath = _alpm_db_path(db);
+	if(dbpath == NULL) {
+		RET_ERR(PM_ERR_DB_OPEN, -1);
+	}
+	dbdir = opendir(dbpath);
+	if(dbdir == NULL) {
+		if(errno == ENOENT) {
+			/* database dir doesn't exist yet */
+			version = 2;
+			goto done;
+		} else {
+			RET_ERR(PM_ERR_DB_OPEN, -1);
+		}
+	}
+
+	while((ent = readdir(dbdir)) != NULL) {
+		const char *name = ent->d_name;
+		char path[PATH_MAX];
+
+		if(strcmp(name, ".") == 0 || strcmp(name, "..") == 0) {
+			continue;
+		}
+		if(!is_dir(dbpath, ent)) {
+			continue;
+		}
+
+		snprintf(path, PATH_MAX, "%s%s/depends", dbpath, name);
+		if(access(path, F_OK) == 0) {
+			/* we found a depends file- bail */
+			version = 1;
+			goto done;
+		}
+	}
+	/* we found no depends file after full scan */
+	version = 2;
+
+done:
+	if(dbdir) {
+		closedir(dbdir);
+	}
+
+	_alpm_log(PM_LOG_DEBUG, "local database version %d\n", version);
+	return(version);
+}
+
 struct db_operations local_db_ops = {
 	.populate         = local_db_populate,
 	.unregister       = _alpm_db_unregister,
+	.version          = local_db_version,
 };
 
 pmdb_t *_alpm_db_register_local(void)