From be6a441edea5fd4e2aab0710c9f65bbd005b9338 Mon Sep 17 00:00:00 2001
From: Zach Musgrave <zach@dolthub.com>
Date: Mon, 20 Sep 2021 10:12:24 -0700
Subject: [PATCH] Rebase on transaction start

---
 go/libraries/doltcore/doltdb/doltdb.go      | 6 ++++++
 go/libraries/doltcore/sqle/dsess/session.go | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/go/libraries/doltcore/doltdb/doltdb.go b/go/libraries/doltcore/doltdb/doltdb.go
index 567e1de626..32f24a3f08 100644
--- a/go/libraries/doltcore/doltdb/doltdb.go
+++ b/go/libraries/doltcore/doltdb/doltdb.go
@@ -1129,6 +1129,12 @@ func (ddb *DoltDB) DeleteWorkspace(ctx context.Context, workRef ref.DoltRef) err
 	return err
 }
 
+// Rebase rebases the underlying db from disk, re-loading the manifest. Useful when another process might have made
+// changes to the database we need to read.
+func (ddb *DoltDB) Rebase(ctx context.Context) error {
+	return ddb.db.Rebase(ctx)
+}
+
 // GC performs garbage collection on this ddb. Values passed in |uncommitedVals| will be temporarily saved during gc.
 func (ddb *DoltDB) GC(ctx context.Context, uncommitedVals ...hash.Hash) error {
 	collector, ok := ddb.db.(datas.GarbageCollector)
diff --git a/go/libraries/doltcore/sqle/dsess/session.go b/go/libraries/doltcore/sqle/dsess/session.go
index 09a752c11e..ab399c3bad 100644
--- a/go/libraries/doltcore/sqle/dsess/session.go
+++ b/go/libraries/doltcore/sqle/dsess/session.go
@@ -281,8 +281,14 @@ func (sess *Session) StartTransaction(ctx *sql.Context, dbName string) (sql.Tran
 		return DisabledTransaction{}, nil
 	}
 
+	err = sessionState.dbData.Ddb.Rebase(ctx)
+	if err != nil {
+		return nil, err
+	}
+
 	wsRef := sessionState.WorkingSet.Ref()
 	ws, err := sessionState.dbData.Ddb.ResolveWorkingSet(ctx, wsRef)
+	// TODO: every HEAD needs a working set created when it is. We can get rid of this in a 1.0 release when this is fixed
 	if err == doltdb.ErrWorkingSetNotFound {
 		ws, err = sess.newWorkingSetForHead(ctx, wsRef, dbName)
 		if err != nil {