filer: clean up manifest resolve error propagation and add webdav tes… (#11297)

filer: clean up manifest resolve error propagation and add webdav test (#78)

Drop GitHub issue references from comments and trim verbose comments.
Replace the viewFromChunksOrErr helper with the existing
NonOverlappingVisibleIntervals + ViewFromVisibleIntervals at the stream
call sites, and add a WebDavFile.Read regression test for the manifest
resolution failure path.

Co-authored-by: Chris Lu <chrislusf@users.noreply.github.com>

weed/server/webdav_server.go

@@ -570,7 +570,6 @@ func (f *WebDavFile) Read(p []byte) (readSize int, err error) {
 	if f.visibleIntervals == nil {
 		f.visibleIntervals, err = filer.NonOverlappingVisibleIntervals(f.ctx, f.fs.filerClient.GetLookupFileIdFunction(), f.entry.GetChunks(), 0, fileSize)
 		if err != nil {
-			// fail instead of streaming zeros for unresolved manifest chunks
 			return 0, err
 		}
 		f.reader = nil

weed/server/webdav_server_test.go

@@ -2,13 +2,20 @@ package weed_server
 
 import (
 	"context"
+	"fmt"
+	"net"
 	"os"
 	"testing"
 
 	"golang.org/x/net/webdav"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 
+	"github.com/seaweedfs/seaweedfs/weed/pb"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"github.com/seaweedfs/seaweedfs/weed/util"
+	"github.com/seaweedfs/seaweedfs/weed/wdclient"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestToFileInfoName(t *testing.T) {
@@ -54,3 +61,46 @@ func TestFileInfoETag(t *testing.T) {
 		t.Errorf("ETag() = %v, want the stat error", err)
 	}
 }
+
+type noVolumeFiler struct {
+	filer_pb.UnimplementedSeaweedFilerServer
+}
+
+func (f *noVolumeFiler) LookupVolume(_ context.Context, _ *filer_pb.LookupVolumeRequest) (*filer_pb.LookupVolumeResponse, error) {
+	return &filer_pb.LookupVolumeResponse{LocationsMap: map[string]*filer_pb.Locations{}}, nil
+}
+
+func startFakeWebDavFiler(t *testing.T, impl filer_pb.SeaweedFilerServer) pb.ServerAddress {
+	t.Helper()
+	lis, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	srv := grpc.NewServer()
+	filer_pb.RegisterSeaweedFilerServer(srv, impl)
+	go srv.Serve(lis)
+	t.Cleanup(srv.Stop)
+	port := lis.Addr().(*net.TCPAddr).Port
+	return pb.ServerAddress(fmt.Sprintf("127.0.0.1:1.%d", port))
+}
+
+// WebDavFile.Read must fail when chunk manifest resolution fails, instead of streaming zeros.
+func TestWebDavFile_Read_ManifestResolveFailure(t *testing.T) {
+	filerAddr := startFakeWebDavFiler(t, &noVolumeFiler{})
+	fc := wdclient.NewFilerClient([]pb.ServerAddress{filerAddr}, grpc.WithTransportCredentials(insecure.NewCredentials()), "")
+	t.Cleanup(fc.Close)
+
+	fs := &WebDavFileSystem{filerClient: fc}
+	entry := &filer_pb.Entry{
+		Name:       "file",
+		Attributes: &filer_pb.FuseAttributes{FileSize: 1 << 20},
+		Chunks: []*filer_pb.FileChunk{
+			{FileId: "1,1679011dc64abd40", IsChunkManifest: true, Offset: 0, Size: 1 << 20},
+		},
+	}
+	f := &WebDavFile{fs: fs, name: "/file", entry: entry, ctx: context.Background()}
+
+	n, err := f.Read(make([]byte, 16))
+	assert.Error(t, err)
+	assert.Equal(t, 0, n)
+}