Prune the right number of excess finalised events

AndrewFerr · AndrewFerr · commit ea6b3ca13298 · 2025-10-31T13:17:13.000-04:00
diff --git a/synapse/storage/databases/main/delayed_events.py b/synapse/storage/databases/main/delayed_events.py
@@ -307,7 +307,8 @@ def _prune_excess_finalised_delayed_events_for_user(
             keyvalues={"user_localpart": user_localpart},
             retcol="COUNT(*)",
         )
-        if num_existing > retention_limit:
+        num_excess = num_existing - retention_limit
+        if num_existing > 0:
             txn.execute(
                 """
                 DELETE FROM delayed_events
@@ -321,7 +322,7 @@ def _prune_excess_finalised_delayed_events_for_user(
                 """,
                 (
                     user_localpart,
-                    num_existing - retention_limit,
+                    num_existing - num_existing,
                 ),
             )
 

Original file line number	Diff line number	Diff line change
`@@ -307,7 +307,8 @@ def _prune_excess_finalised_delayed_events_for_user(`
`307`	`307`	`keyvalues={"user_localpart": user_localpart},`
`308`	`308`	`retcol="COUNT(*)",`
`309`	`309`	`)`
`310`		`- if num_existing > retention_limit:`
	`310`	`+ num_excess = num_existing - retention_limit`
	`311`	`+ if num_existing > 0:`
`311`	`312`	`txn.execute(`
`312`	`313`	`"""`
`313`	`314`	`DELETE FROM delayed_events`
`@@ -321,7 +322,7 @@ def _prune_excess_finalised_delayed_events_for_user(`
`321`	`322`	`""",`
`322`	`323`	`(`
`323`	`324`	`user_localpart,`
`324`		`- num_existing - retention_limit,`
	`325`	`+ num_existing - num_existing,`
`325`	`326`	`),`
`326`	`327`	`)`
`327`	`328`