storage: Don't read bad completed piece files

diff --git a/storage/piece_file.go b/storage/piece_file.go
index c9fc3c2187f6327bceabf5980590c1522e19ed3b..95b2af0b9ee3e279e2775e0d6d3dc9c7177fe64d 100644 (file)
--- a/storage/piece_file.go
+++ b/storage/piece_file.go
@@ -59,22 +59,37 @@ func (me pieceFileTorrentStoragePiece) MarkComplete() error {
        return me.fs.Rename(me.incompletePath(), me.completedPath())
 }
 
-func (me pieceFileTorrentStoragePiece) ReadAt(b []byte, off int64) (n int, err error) {
-       f, err := me.fs.OpenFile(me.completedPath(), os.O_RDONLY)
-       if err != nil {
-               f, err = me.fs.OpenFile(me.incompletePath(), os.O_RDONLY)
-               if os.IsNotExist(err) {
-                       err = io.ErrUnexpectedEOF
-                       return
-               }
-               if err != nil {
+func (me pieceFileTorrentStoragePiece) openFile() (f missinggo.File, err error) {
+       f, err = me.fs.OpenFile(me.completedPath(), os.O_RDONLY)
+       if err == nil {
+               var fi os.FileInfo
+               fi, err = f.Stat()
+               if err == nil && fi.Size() == me.p.Length() {
                        return
                }
+               f.Close()
+       } else if !os.IsNotExist(err) {
+               return
+       }
+       f, err = me.fs.OpenFile(me.incompletePath(), os.O_RDONLY)
+       if os.IsNotExist(err) {
+               err = io.ErrUnexpectedEOF
+       }
+       return
+}
+
+func (me pieceFileTorrentStoragePiece) ReadAt(b []byte, off int64) (n int, err error) {
+       f, err := me.openFile()
+       if err != nil {
+               return
        }
        defer f.Close()
+       missinggo.LimitLen(&b, me.p.Length()-off)
        n, err = f.ReadAt(b, off)
        off += int64(n)
-       if err == io.EOF && off < me.p.Length() {
+       if off >= me.p.Length() {
+               err = io.EOF
+       } else if err == io.EOF {
                err = io.ErrUnexpectedEOF
        }
        return