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