Merge pull request #2738 from git-lfs/migrate-assume-current

commands/migrate: add '--skip-fetch' for offline migrations

commands/command_migrate.go

@@ -21,6 +21,11 @@ var (
 	// in the migration.
 	migrateExcludeRefs []string
 
+	// migrateSkipFetch assumes that the client has the latest copy of
+	// remote references, and thus should not contact the remote for a set
+	// of updated references.
+	migrateSkipFetch bool
+
 	// migrateEverything indicates the presence of the --everything flag,
 	// and instructs 'git lfs migrate' to migrate all local references.
 	migrateEverything bool
@@ -174,14 +179,22 @@ func getRemoteRefs(l *log.Logger) ([]*git.Ref, error) {
 		return nil, err
 	}
 
+	if !migrateSkipFetch {
 		w := l.Waiter("migrate: Fetching remote refs")
 		if err := git.Fetch(remotes...); err != nil {
 			return nil, err
 		}
 		w.Complete()
+	}
 
 	for _, remote := range remotes {
-		refsForRemote, err := git.RemoteRefs(remote)
+		var refsForRemote []*git.Ref
+		if migrateSkipFetch {
+			refsForRemote, err = git.CachedRemoteRefs(remote)
+		} else {
+			refsForRemote, err = git.RemoteRefs(remote)
+		}
+
 		if err != nil {
 			return nil, err
 		}
@@ -259,6 +272,7 @@ func init() {
 		cmd.PersistentFlags().StringSliceVar(&migrateIncludeRefs, "include-ref", nil, "An explicit list of refs to include")
 		cmd.PersistentFlags().StringSliceVar(&migrateExcludeRefs, "exclude-ref", nil, "An explicit list of refs to exclude")
 		cmd.PersistentFlags().BoolVar(&migrateEverything, "everything", false, "Migrate all local references")
+		cmd.PersistentFlags().BoolVar(&migrateSkipFetch, "skip-fetch", false, "Assume up-to-date remote references.")
 
 		cmd.AddCommand(importCmd, info)
 	})

docs/man/git-lfs-migrate.1.ronn

@@ -27,6 +27,11 @@ git-lfs-migrate(1) - Migrate history to or from git-lfs
 * `--exclude-ref`=<refname>:
     See [INCLUDE AND EXCLUDE (REFS)].
 
+* `--skip-fetch`:
+    Assumes that the known set of remote references is complete, and should not
+    be refreshed when determining the set of "un-pushed" commits to migrate. Has
+    no effect when combined with `--include-ref` or `--exclude-ref`.
+
 * `--everything`:
     See [INCLUDE AND EXCLUDE (REFS)].
 

test/test-migrate-import.sh

@@ -202,6 +202,47 @@ begin_test "migrate import (given branch, exclude remote refs)"
 )
 end_test
 
+begin_test "migrate import (given ref, --skip-fetch)"
+(
+  set -e
+
+  setup_single_remote_branch
+
+  md_master_oid="$(calc_oid "$(git cat-file -p "refs/heads/master:a.md")")"
+  md_remote_oid="$(calc_oid "$(git cat-file -p "refs/remotes/origin/master:a.md")")"
+  txt_master_oid="$(calc_oid "$(git cat-file -p "refs/heads/master:a.txt")")"
+  txt_remote_oid="$(calc_oid "$(git cat-file -p "refs/remotes/origin/master:a.txt")")"
+
+  git tag pseudo-remote "$(git rev-parse refs/remotes/origin/master)"
+  # Remove the refs/remotes/origin/master ref, and instruct 'git lfs migrate' to
+  # not fetch it.
+  git update-ref -d refs/remotes/origin/master
+
+  git lfs migrate import --skip-fetch
+
+  assert_pointer "refs/heads/master" "a.md" "$md_master_oid" "50"
+  assert_pointer "pseudo-remote" "a.md" "$md_remote_oid" "140"
+  assert_pointer "refs/heads/master" "a.txt" "$txt_master_oid" "30"
+  assert_pointer "pseudo-remote" "a.txt" "$txt_remote_oid" "120"
+
+  assert_local_object "$md_master_oid" "50"
+  assert_local_object "$txt_master_oid" "30"
+  assert_local_object "$md_remote_oid" "140"
+  assert_local_object "$txt_remote_oid" "120"
+
+  master="$(git rev-parse refs/heads/master)"
+  remote="$(git rev-parse pseudo-remote)"
+
+  master_attrs="$(git cat-file -p "$master:.gitattributes")"
+  remote_attrs="$(git cat-file -p "$remote:.gitattributes")"
+
+  echo "$master_attrs" | grep -q "*.md filter=lfs diff=lfs merge=lfs"
+  echo "$master_attrs" | grep -q "*.txt filter=lfs diff=lfs merge=lfs"
+  echo "$remote_attrs" | grep -q "*.md filter=lfs diff=lfs merge=lfs"
+  echo "$remote_attrs" | grep -q "*.txt filter=lfs diff=lfs merge=lfs"
+)
+end_test
+
 begin_test "migrate import (include/exclude ref)"
 (
   set -e

test/test-migrate-info.sh

@@ -132,6 +132,33 @@ begin_test "migrate info (given branch, exclude remote refs)"
 )
 end_test
 
+begin_test "migrate info (given ref, --skip-fetch)"
+(
+  set -e
+
+  setup_single_remote_branch
+
+  original_remote="$(git rev-parse refs/remotes/origin/master)"
+  original_master="$(git rev-parse refs/heads/master)"
+
+  git tag pseudo-remote "$original_remote"
+  # Remove the refs/remotes/origin/master ref, and instruct 'git lfs migrate' to
+  # not fetch it.
+  git update-ref -d refs/remotes/origin/master
+
+  diff -u <(git lfs migrate info --skip-fetch 2>&1 | tail -n 2) <(cat <<-EOF
+	*.md 	190 B	2/2 files(s)	100%
+	*.txt	150 B	2/2 files(s)	100%
+	EOF)
+
+  migrated_remote="$(git rev-parse pseudo-remote)"
+  migrated_master="$(git rev-parse refs/heads/master)"
+
+  assert_ref_unmoved "refs/remotes/origin/master" "$original_remote" "$migrated_remote"
+  assert_ref_unmoved "refs/heads/master" "$original_master" "$migrated_master"
+)
+end_test
+
 begin_test "migrate info (include/exclude ref)"
 (
   set -e