Skip to content

mcp: prevent MemoryEventStore.After panic on index past the end #1132

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
guglielmo-san merged 4 commits into from
Aug 21, 2026
+10 −3
Merged

mcp: prevent MemoryEventStore.After panic on index past the end #1132

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
102946a
mcp: prevent MemoryEventStore.After panic on index past the end
PratikDhanave Aug 2, 2026
93fb483
Merge branch 'main' into fix/eventstore-after-oob
PratikDhanave Aug 21, 2026
5507593
simplify:
yarolegovich Aug 21, 2026
87d58ee
Merge branch 'main' into fix/eventstore-after-oob
yarolegovich Aug 21, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 6 additions & 3 deletions mcp/event.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -337,12 +337,15 @@ func (s *MemoryEventStore) After(_ context.Context, sessionID, streamID string,
if !ok {
return nil, fmt.Errorf("MemoryEventStore.After: unknown stream ID %v in session %q", streamID, sessionID)
}
start := index + 1
if dl.first > start {
start := (index + 1) - dl.first
if start < 0 {
return nil, fmt.Errorf("MemoryEventStore.After: index %d, stream ID %v, session %q: %w",
index, streamID, sessionID, ErrEventsPurged)
}
return slices.Clone(dl.data[start-dl.first:]), nil
if start >= len(dl.data) {
return nil, nil
}
return slices.Clone(dl.data[start:]), nil
}

return func(yield func([]byte, error) bool) {
Expand Down
4 changes: 4 additions & 0 deletions mcp/event_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -299,7 +299,11 @@ func TestMemoryEventStoreAfter(t *testing.T) {
{"S1", "1", 0, []string{"d2", "d3"}, ""},
{"S1", "1", 1, []string{"d3"}, ""},
{"S1", "1", 2, nil, ""},
{"S1", "1", 3, nil, ""},
{"S1", "1", 100, nil, ""}, // past the end of stream "1" (highest is 2)
{"S1", "2", 0, nil, ""},
{"S1", "2", 1, nil, ""},
{"S1", "2", 100, nil, ""},
{"S1", "3", 0, nil, "unknown stream ID"},
{"S2", "0", 0, nil, "unknown session ID"},
} {
Expand Down
Loading