From cdbe5d52c271dd91262e4bf9219928f957e42f23 Mon Sep 17 00:00:00 2001
From: nexy7574 <git@nexy7574.co.uk>
Date: Mon, 26 May 2025 02:32:44 +0100
Subject: [PATCH] force 0ns timeouts to default appropriately in syncv3

---
 src/api/client/sync/v3.rs | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/api/client/sync/v3.rs b/src/api/client/sync/v3.rs
index 8eac6b66..2c7ec5b4 100644
--- a/src/api/client/sync/v3.rs
+++ b/src/api/client/sync/v3.rs
@@ -1,18 +1,18 @@
 use std::{
-	cmp::{self},
 	collections::{BTreeMap, HashMap, HashSet},
 	time::Duration,
 };
 
 use axum::extract::State;
 use conduwuit::{
-	Result, at, err, error, extract_variant, is_equal_to,
+	Result, at, debug, debug_warn, err, error, extract_variant, is_equal_to,
 	matrix::{
 		Event,
 		pdu::{EventHash, PduCount, PduEvent},
 	},
 	pair_of, ref_at,
 	result::FlatOk,
+	trace,
 	utils::{
 		self, BoolExt, FutureBoolExt, IterStream, ReadyExt, TryFutureExtExt,
 		future::{OptionStream, ReadyEqExt},
@@ -133,8 +133,13 @@ pub(crate) async fn sync_events_route(
 
 	// Setup watchers, so if there's no response, we can wait for them
 	let watcher = services.sync.watch(sender_user, sender_device);
-
 	let response = build_sync_events(&services, &body).await?;
+	trace!("sync body.body.full_state: {}", body.body.full_state);
+	trace!("response.rooms.is_empty(): {}", response.rooms.is_empty());
+	trace!("response.presence.is_empty(): {}", response.presence.is_empty());
+	trace!("response.account_data.is_empty(): {}", response.account_data.is_empty());
+	trace!("response.device_lists.is_empty(): {}", response.device_lists.is_empty());
+	trace!("response.to_device.is_empty(): {}", response.to_device.is_empty());
 	if body.body.full_state
 		|| !(response.rooms.is_empty()
 			&& response.presence.is_empty()
@@ -142,17 +147,29 @@ pub(crate) async fn sync_events_route(
 			&& response.device_lists.is_empty()
 			&& response.to_device.is_empty())
 	{
+		trace!("Sync response built and returning immediately: {response:#?}");
 		return Ok(response);
 	}
 
 	// Hang a few seconds so requests are not spammed
 	// Stop hanging if new info arrives
-	let default = Duration::from_secs(30);
-	let duration = cmp::min(body.body.timeout.unwrap_or(default), default);
-	_ = tokio::time::timeout(duration, watcher).await;
+	let default_timeout = Duration::from_secs(30);
+	let user_timeout = body.body.timeout.unwrap_or(default_timeout);
+	trace!("User timeout: {user_timeout:?}, default timeout: {default_timeout:?}");
+	// If the user default resolves to 0ns or less, use the default timeout
+	let timeout = if user_timeout <= Duration::from_secs(0) {
+		default_timeout
+	} else {
+		user_timeout
+	};
+	debug!("Sync was empty, waiting for new data for {timeout:?}");
+	_ = tokio::time::timeout(timeout, watcher).await;
 
 	// Retry returning data
-	build_sync_events(&services, &body).await
+	trace!("Sync watcher returned, retrying build_sync_events");
+	let new_response = build_sync_events(&services, &body).await?;
+	trace!("Sync watcher returned, built new response: {new_response:#?}");
+	Ok(new_response)
 }
 
 pub(crate) async fn build_sync_events(