retry: abort retry loop on context errors (#1383)

Fixes #1377

internal/retry/retry.go

@@ -56,6 +56,11 @@ func internalRetry(ctx context.Context, desc string, attempt AttemptFunc, isRetr
 	var lastError error
 
 	for i := 0; i < count; i++ {
+		if cerr := ctx.Err(); cerr != nil {
+			// nolint:wrapcheck
+			return nil, cerr
+		}
+
 		v, err := attempt()
 		if err == nil {
 			return v, nil

internal/retry/retry_test.go

@@ -1,10 +1,12 @@
 package retry
 
 import (
+	"context"
 	"testing"
 	"time"
 
 	"github.com/pkg/errors"
+	"github.com/stretchr/testify/require"
 
 	"github.com/kopia/kopia/internal/testlogging"
 )
@@ -58,3 +60,16 @@ func TestRetry(t *testing.T) {
 		})
 	}
 }
+
+func TestRetryContextCancel(t *testing.T) {
+	t.Parallel()
+
+	ctx := testlogging.Context(t)
+
+	canceledctx, cancel := context.WithCancel(ctx)
+	cancel()
+
+	require.ErrorIs(t, context.Canceled, WithExponentialBackoffNoValue(canceledctx, "canceled", func() error {
+		return errRetriable
+	}, isRetriable))
+}