From 506499633bf4486e340d94616f41d7848c5d2061 Mon Sep 17 00:00:00 2001 From: Kegan Dougal Date: Wed, 4 Aug 2021 16:25:15 +0100 Subject: [PATCH] bugfix: sqlite migration should handle create events as having no 'before' snapshot The state snapshot for any given event in the roomserver represents the state _before_ the event. For the create event, this is nothing, so the state snapshot nid should be 0. In some cases this wasn't happening, resulting in a nice mix of possible options including: - A state snapshot without any state blocks `[]` or `null`. - A state snapshot with a single state block with a single event, the create event, causing a circular loop. This is incorrect as it represents the state before the event, not after. --- .../2021041615092700_state_blocks_refactor.go | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/roomserver/storage/sqlite3/deltas/2021041615092700_state_blocks_refactor.go b/roomserver/storage/sqlite3/deltas/2021041615092700_state_blocks_refactor.go index 42edbbc6f..0cf1f733a 100644 --- a/roomserver/storage/sqlite3/deltas/2021041615092700_state_blocks_refactor.go +++ b/roomserver/storage/sqlite3/deltas/2021041615092700_state_blocks_refactor.go @@ -93,6 +93,20 @@ func UpStateBlocksRefactor(tx *sql.Tx) error { } var newblocks types.StateBlockNIDs + if len(blocks) == 0 { + // some m.room.create events have a state snapshot but no state blocks at all which makes + // sense as there is no state before creation. The correct form should be to give the event + // in question a state snapshot NID of 0 to indicate 'no snapshot'. + // If we don't do this, we'll fail the assertions later on which try to ensure we didn't forget + // any snapshots. + _, err = tx.Exec( + `UPDATE roomserver_events SET state_snapshot_nid = 0 WHERE event_type_nid = $1 AND state_snapshot_nid = $2`, + types.MRoomCreateNID, snapshot, + ) + if err != nil { + return fmt.Errorf("resetting create events snapshots to 0 errored: %s", err) + } + } for _, block := range blocks { if err = func() error { blockrows, berr := tx.Query(`SELECT event_nid FROM _roomserver_state_block WHERE state_block_nid = $1`, block)