From 4408ece955b946056cc0cb4d02d7538167842ac3 Mon Sep 17 00:00:00 2001
From: Ben Schumacher <ben.schumacher@mattermost.com>
Date: Mon, 16 Oct 2023 22:40:19 +0200
Subject: [PATCH] Fix data race in bulk import tests (#24897)

---
 server/channels/app/import.go                 |  2 +-
 .../channels/store/sqlstore/context_test.go   | 46 +++++++++++++++++++
 server/public/shared/request/context.go       |  7 +++
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/server/channels/app/import.go b/server/channels/app/import.go
index c877581f52..1997862db2 100644
--- a/server/channels/app/import.go
+++ b/server/channels/app/import.go
@@ -268,7 +268,7 @@ func (a *App) bulkImport(c request.CTX, jsonlReader io.Reader, attachmentsReader
 			linesChan = make(chan imports.LineImportWorkerData, workers)
 			for i := 0; i < workers; i++ {
 				wg.Add(1)
-				go a.bulkImportWorker(c, dryRun, &wg, linesChan, errorsChan)
+				go a.bulkImportWorker(c.Clone(), dryRun, &wg, linesChan, errorsChan)
 			}
 		}
 
diff --git a/server/channels/store/sqlstore/context_test.go b/server/channels/store/sqlstore/context_test.go
index 43d3332578..e477cb3c56 100644
--- a/server/channels/store/sqlstore/context_test.go
+++ b/server/channels/store/sqlstore/context_test.go
@@ -7,6 +7,7 @@ import (
 	"context"
 	"testing"
 
+	"github.com/mattermost/mattermost/server/public/shared/request"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -16,3 +17,48 @@ func TestContextMaster(t *testing.T) {
 	m := WithMaster(ctx)
 	assert.True(t, HasMaster(m))
 }
+
+func TestRequestContextWithMaster(t *testing.T) {
+	t.Run("set and get", func(t *testing.T) {
+		var rctx request.CTX = request.TestContext(t)
+
+		rctx = RequestContextWithMaster(rctx)
+		assert.True(t, HasMaster(rctx.Context()))
+	})
+
+	t.Run("directly assigning does cause the child to alter the parent", func(t *testing.T) {
+		var rctx request.CTX = request.TestContext(t)
+		rctxClone := rctx
+		rctxClone = RequestContextWithMaster(rctxClone)
+
+		assert.True(t, HasMaster(rctx.Context()))
+		assert.True(t, HasMaster(rctxClone.Context()))
+	})
+
+	t.Run("values get copied from parent", func(t *testing.T) {
+		var rctx request.CTX = request.TestContext(t)
+		rctx = RequestContextWithMaster(rctx)
+		rctxClone := rctx.Clone()
+
+		assert.True(t, HasMaster(rctx.Context()))
+		assert.True(t, HasMaster(rctxClone.Context()))
+	})
+
+	t.Run("changing the child does not alter the parent", func(t *testing.T) {
+		var rctx request.CTX = request.TestContext(t)
+		rctxClone := rctx.Clone()
+		rctxClone = RequestContextWithMaster(rctxClone)
+
+		assert.False(t, HasMaster(rctx.Context()))
+		assert.True(t, HasMaster(rctxClone.Context()))
+	})
+
+	t.Run("changing the parent does not alter the child", func(t *testing.T) {
+		var rctx request.CTX = request.TestContext(t)
+		rctxClone := rctx.Clone()
+		rctx = RequestContextWithMaster(rctx)
+
+		assert.True(t, HasMaster(rctx.Context()))
+		assert.False(t, HasMaster(rctxClone.Context()))
+	})
+}
diff --git a/server/public/shared/request/context.go b/server/public/shared/request/context.go
index 3e43611287..bd073794cd 100644
--- a/server/public/shared/request/context.go
+++ b/server/public/shared/request/context.go
@@ -54,6 +54,12 @@ func TestContext(t testing.TB) *Context {
 	return EmptyContext(logger)
 }
 
+// Clone creates a shallow copy of Context, allowing clones to apply per-request changes.
+func (c *Context) Clone() CTX {
+	cCopy := *c
+	return &cCopy
+}
+
 func (c *Context) T(translationID string, args ...any) string {
 	return c.t(translationID, args...)
 }
@@ -125,6 +131,7 @@ func (c *Context) Logger() mlog.LoggerIFace {
 }
 
 type CTX interface {
+	Clone() CTX
 	T(string, ...interface{}) string
 	Session() *model.Session
 	RequestId() string