validate ws migration, skip table validation if table did not change (#4630)

go/libraries/doltcore/migrate/transform.go

@@ -74,6 +74,16 @@ func migrateWorkingSet(ctx context.Context, brRef ref.BranchRef, wsRef ref.Worki
 		return err
 	}
 
+	err = validateRootValue(ctx, oldHeadRoot, oldWs.WorkingRoot(), wr)
+	if err != nil {
+		return err
+	}
+
+	err = validateRootValue(ctx, oldHeadRoot, oldWs.StagedRoot(), sr)
+	if err != nil {
+		return err
+	}
+
 	newWs := doltdb.EmptyWorkingSet(wsRef).WithWorkingRoot(wr).WithStagedRoot(sr)
 
 	return new.UpdateWorkingSet(ctx, wsRef, newWs, hash.Hash{}, oldWs.Meta())
@@ -179,7 +189,7 @@ func migrateCommit(ctx context.Context, oldCm *doltdb.Commit, new *doltdb.DoltDB
 
 	// validate root after we flush the ChunkStore to facilitate
 	// investigating failed migrations
-	if err = validateRootValue(ctx, oldRoot, mRoot); err != nil {
+	if err = validateRootValue(ctx, oldParentRoot, oldRoot, mRoot); err != nil {
 		return err
 	}
 

go/libraries/doltcore/migrate/validation.go

@@ -52,7 +52,7 @@ func validateBranchMapping(ctx context.Context, old, new *doltdb.DoltDB) error {
 	return nil
 }
 
-func validateRootValue(ctx context.Context, old, new *doltdb.RootValue) error {
+func validateRootValue(ctx context.Context, oldParent, old, new *doltdb.RootValue) error {
 	names, err := old.GetTableNames(ctx)
 	if err != nil {
 		return err
@@ -67,6 +67,25 @@ func validateRootValue(ctx context.Context, old, new *doltdb.RootValue) error {
 			return fmt.Errorf("expected to find table %s in root value (%s)", name, h.String())
 		}
 
+		// Skip tables that haven't changed
+		op, ok, err := oldParent.GetTable(ctx, name)
+		if err != nil {
+			return err
+		}
+		if ok {
+			oldHash, err := o.HashOf()
+			if err != nil {
+				return err
+			}
+			oldParentHash, err := op.HashOf()
+			if err != nil {
+				return err
+			}
+			if oldHash.Equal(oldParentHash) {
+				continue
+			}
+		}
+
 		n, ok, err := new.GetTable(ctx, name)
 		if err != nil {
 			return err