From 623770eebbf30315e24685aa3c68b8dc633c3c79 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Sun, 17 Jul 2022 12:11:54 +0200
Subject: [PATCH] repository: try to recover from invalid blob while repacking

If a blob that should be kept is invalid, Repack will now try to request
the blob using LoadBlob. Only return an error if that fails.
---
 internal/repository/repack.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/internal/repository/repack.go b/internal/repository/repack.go
index 0a50bfcf4..bf6b65c8f 100644
--- a/internal/repository/repack.go
+++ b/internal/repository/repack.go
@@ -73,7 +73,13 @@ func repack(ctx context.Context, repo restic.Repository, dstRepo restic.Reposito
 		for t := range downloadQueue {
 			err := StreamPack(wgCtx, repo.Backend().Load, repo.Key(), t.PackID, t.Blobs, func(blob restic.BlobHandle, buf []byte, err error) error {
 				if err != nil {
-					return err
+					var ierr error
+					// check whether we can get a valid copy somewhere else
+					buf, ierr = repo.LoadBlob(wgCtx, blob.Type, blob.ID, nil)
+					if ierr != nil {
+						// no luck, return the original error
+						return err
+					}
 				}
 
 				keepMutex.Lock()