in src/main/java/com/googlesource/gerrit/plugins/refprotection/BackupRef.java [203:223]
private static String getSequentialBranch(ProjectResource project, String branchName) {
Integer rev = 1;
String deletedName = branchName.replaceFirst(R_REFS, "");
try (Repository git = repoManager.openRepository(project.getNameKey())) {
for (Ref ref : git.getRefDatabase().getRefs()) {
String name = ref.getName();
if (name.startsWith(R_BACKUPS + deletedName + "/")) {
Integer thisNum = Integer.parseInt(name.substring(name.lastIndexOf('/') + 1));
if (thisNum >= rev) {
rev = thisNum + 1;
}
}
}
} catch (RepositoryNotFoundException e) {
log.error("Repository does not exist", e);
} catch (IOException e) {
log.error("Could not determine latest revision of deleted branch", e);
}
return R_BACKUPS + deletedName + "/" + rev;
}