Fix an issue where contexts are not copied correctly (#1941)

Fix an issue in the Stasher where contexts between the request and log entry are not copied correctly.

Co-authored-by: ouyangxu <ouyangxu@bilibili.com>

pkg/download/protocol.go

@@ -298,7 +298,7 @@ func union(list1, list2 []string) []string {
 
 func copyContextWithCustomTimeout(ctx context.Context, timeout time.Duration) (context.Context, context.CancelFunc) {
 	ctxCopy, cancel := context.WithTimeout(context.Background(), timeout)
-	requestid.SetInContext(ctxCopy, requestid.FromContext(ctx))
-	log.SetEntryInContext(ctxCopy, log.EntryFromContext(ctx))
+	ctxCopy = requestid.SetInContext(ctxCopy, requestid.FromContext(ctx))
+	ctxCopy = log.SetEntryInContext(ctxCopy, log.EntryFromContext(ctx))
 	return ctxCopy, cancel
 }

pkg/download/protocol_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/gomods/athens/pkg/download/mode"
 	"github.com/gomods/athens/pkg/errors"
 	"github.com/gomods/athens/pkg/index/nop"
+	"github.com/gomods/athens/pkg/log"
 	"github.com/gomods/athens/pkg/module"
 	"github.com/gomods/athens/pkg/stash"
 	"github.com/gomods/athens/pkg/storage"
@@ -495,3 +496,38 @@ func (ml *mockLister) List(ctx context.Context, mod string) (*storage.RevInfo, [
 	ml.called = true
 	return nil, ml.list, ml.err
 }
+
+type testEntry struct {
+	msg string
+}
+
+var _ log.Entry = &testEntry{}
+
+func (e *testEntry) Debugf(format string, args ...any) {
+	e.msg = format
+}
+func (*testEntry) Infof(format string, args ...any)           {}
+func (*testEntry) Warnf(format string, args ...any)           {}
+func (*testEntry) Errorf(format string, args ...any)          {}
+func (*testEntry) WithFields(fields map[string]any) log.Entry { return nil }
+func (*testEntry) SystemErr(err error)                        {}
+
+func Test_copyContextWithCustomTimeout(t *testing.T) {
+	testEntry := &testEntry{}
+
+	// create a context with a logger entry
+	logctx := log.SetEntryInContext(context.Background(), testEntry)
+
+	// check the log work as expected
+	log.EntryFromContext(logctx).Debugf("first test")
+	require.Equal(t, "first test", testEntry.msg)
+
+	// use copyContextWithCustomTimeout to create a new context with a custom timeout,
+	// and the returned context should have the same logger entry
+	newCtx, cancel := copyContextWithCustomTimeout(logctx, 10*time.Second)
+	defer cancel()
+
+	// check the log work as expected
+	log.EntryFromContext(newCtx).Debugf("second test")
+	require.Equal(t, "second test", testEntry.msg)
+}