From ca918c187dc52653bcbd88a72e77088def8ac753 Mon Sep 17 00:00:00 2001
From: Nia Weiss <nia.weiss@molecula.com>
Date: Wed, 17 Feb 2021 15:39:22 -0500
Subject: [PATCH] fix a race condition when deferring foreign-index
 initialization

---
 holder.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/holder.go b/holder.go
index 8400f1811..c24d178f1 100644
--- a/holder.go
+++ b/holder.go
@@ -121,7 +121,8 @@ type Holder struct {
 
 	// Queue of fields (having a foreign index) which have
 	// opened before their foreign index has opened.
-	foreignIndexFields []*Field
+	foreignIndexFields   []*Field
+	foreignIndexFieldsMu sync.Mutex
 
 	// opening is set to true while Holder is opening.
 	// It's used to determine if foreign index application
@@ -738,6 +739,8 @@ func (h *Holder) Activate() {
 func (h *Holder) checkForeignIndex(f *Field) error {
 	if h.opening {
 		if fi := h.Index(f.options.ForeignIndex); fi == nil {
+			h.foreignIndexFieldsMu.Lock()
+			defer h.foreignIndexFieldsMu.Unlock()
 			h.foreignIndexFields = append(h.foreignIndexFields, f)
 			return nil
 		}