diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/go/internal/modfetch/sumdb.go | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/cmd/go/internal/modfetch/sumdb.go b/src/cmd/go/internal/modfetch/sumdb.go index b01aad8333..ebfb95b716 100644 --- a/src/cmd/go/internal/modfetch/sumdb.go +++ b/src/cmd/go/internal/modfetch/sumdb.go @@ -233,7 +233,15 @@ func (*dbClient) WriteConfig(file string, old, new []byte) error { // which will be deleted by "go clean -modcache". func (*dbClient) ReadCache(file string) ([]byte, error) { targ := filepath.Join(PkgMod, "download/cache/sumdb", file) - return lockedfile.Read(targ) + data, err := lockedfile.Read(targ) + // lockedfile.Write does not atomically create the file with contents. + // There is a moment between file creation and locking the file for writing, + // during which the empty file can be locked for reading. + // Treat observing an empty file as file not found. + if err == nil && len(data) == 0 { + err = &os.PathError{Op: "read", Path: targ, Err: os.ErrNotExist} + } + return data, err } // WriteCache updates cached lookups or tiles. |