mirrors/etherpad-lite
1
0
Fork 0
mirror of https://github.com/ether/etherpad-lite.git synced 2025-04-21 07:56:16 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

PadMessageHandler: Accept retransmissions of USER_CHANGES

Browse source
This commit is contained in:
Richard Hansen 2021-12-12 18:19:36 -05:00
parent a370cfa5c6
commit cff089e54e
3 changed files with 10 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

14
src/node/handler/PadMessageHandler.js
View file

@ -615,19 +615,15 @@ const handleUserChanges = async (socket, message) => {
// Update the changeset so that it can be applied to the latest revision. // Update the changeset so that it can be applied to the latest revision.
while (r < pad.getHeadRevisionNumber()) { while (r < pad.getHeadRevisionNumber()) {
r++; r++;
const {changeset: c, meta: {author: authorId}} = await pad.getRevision(r);
const c = await pad.getRevisionChangeset(r); if (changeset === c && thisSession.author === authorId) {
// Assume this is a retransmission of an already applied changeset.
rebasedChangeset = Changeset.identity(Changeset.unpack(changeset).oldLen);
}
// At this point, both "c" (from the pad) and "changeset" (from the // At this point, both "c" (from the pad) and "changeset" (from the
// client) are relative to revision r - 1. The follow function // client) are relative to revision r - 1. The follow function
// rebases "changeset" so that it is relative to revision r // rebases "changeset" so that it is relative to revision r
// and can be applied after "c". // and can be applied after "c".
// a changeset can be based on an old revision with the same changes in it
// prevent eplite from accepting it TODO: better send the client a NEW_CHANGES
// of that revision
if (baseRev + 1 === r && c === changeset) throw new Error('Changeset already accepted');
rebasedChangeset = Changeset.follow(c, rebasedChangeset, false, pad.pool); rebasedChangeset = Changeset.follow(c, rebasedChangeset, false, pad.pool);
} }

5
src/static/js/collab_client.js
View file

@ -208,8 +208,9 @@ const getCollabClient = (ace2editor, serverVars, initialUserInfo, options, _pad)
} else if (msg.type === 'ACCEPT_COMMIT') { } else if (msg.type === 'ACCEPT_COMMIT') {
serverMessageTaskQueue.enqueue(() => { serverMessageTaskQueue.enqueue(() => {
const {newRev} = msg; const {newRev} = msg;
// newRev will equal rev if the changeset has no net effect (identity changeset, or removing // newRev will equal rev if the changeset has no net effect (identity changeset, removing
// and re-adding the same characters with the same attributes). // and re-adding the same characters with the same attributes, or retransmission of an
// already applied changeset).
if (![rev, rev + 1].includes(newRev)) { if (![rev, rev + 1].includes(newRev)) {
window.console.warn(`bad message revision on ACCEPT_COMMIT: ${newRev} not ${rev + 1}`); window.console.warn(`bad message revision on ACCEPT_COMMIT: ${newRev} not ${rev + 1}`);
// setChannelState("DISCONNECTED", "badmessage_acceptcommit"); // setChannelState("DISCONNECTED", "badmessage_acceptcommit");

4
src/tests/backend/specs/messages.js
View file

@ -75,12 +75,12 @@ describe(__filename, function () {
await assertRejected(); await assertRejected();
}); });
it('retransmission is rejected', async function () { it('retransmission is accepted, has no effect', async function () {
sendUserChanges('Z:1>5+5$hello'); sendUserChanges('Z:1>5+5$hello');
await assertAccepted(rev + 1); await assertAccepted(rev + 1);
--rev; --rev;
sendUserChanges('Z:1>5+5$hello'); sendUserChanges('Z:1>5+5$hello');
await assertRejected(); await assertAccepted(rev + 1);
assert.equal(pad.text(), 'hello\n'); assert.equal(pad.text(), 'hello\n');
}); });