Make forward backfill timeout configurable

mautrix_telegram/config.py

@@ -194,6 +194,7 @@ class Config(BaseBridgeConfig):
             copy("bridge.backfill.forward_limits.sync.normal_group")
             copy("bridge.backfill.forward_limits.sync.supergroup")
             copy("bridge.backfill.forward_limits.sync.channel")
+        copy("bridge.backfill.forward_timeout")
         copy("bridge.backfill.incremental.messages_per_batch")
         copy("bridge.backfill.incremental.post_batch_delay")
         copy("bridge.backfill.incremental.max_batches.user")

mautrix_telegram/example-config.yaml

@@ -420,6 +420,8 @@ bridge:
                 normal_group: 100
                 supergroup: 100
                 channel: 100
+        # Timeout for forward backfills in seconds. If you have a high limit, you'll have to increase this too.
+        forward_timeout: 900
 
         # Settings for incremental backfill of history. These only apply when using MSC2716.
         incremental:

mautrix_telegram/portal.py

@@ -2885,13 +2885,15 @@ class Portal(DBPortal, BasePortal):
         )
         if limit == 0:
             return "Limit is zero, not backfilling"
+        timeout = self.config["bridge.backfill.forward_timeout"]
         with self.backfill_lock:
-            output = await asyncio.wait_for(
-                self.backfill(
-                    source, client, forward=True, forward_limit=limit, last_tgid=last_tgid
-                ),
-                timeout=15 * 60,
+            task = self.backfill(
+                source, client, forward=True, forward_limit=limit, last_tgid=last_tgid
             )
+            if timeout > 0:
+                output = await asyncio.wait_for(task, timeout=timeout)
+            else:
+                output = await task
             self.log.debug(f"Forward backfill complete, status: {output}")
             return output