From d69429661ad7efb189d2ad8074c867265009d0a4 Mon Sep 17 00:00:00 2001
From: Liu Ming <extrafliu@gmail.com>
Date: Fri, 12 Aug 2016 14:52:07 +0800
Subject: [PATCH] fix the bug of ssat read

---
 ole.go           | 19 ++++++++++++-------
 stream_reader.go | 15 ++++++++-------
 2 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/ole.go b/ole.go
index bb6ebb4..9a2f96a 100644
--- a/ole.go
+++ b/ole.go
@@ -54,9 +54,9 @@ func (o *Ole) ListDir() (dir []*File, err error) {
 	return
 }
 
-func (o *Ole) OpenFile(file *File) io.ReadSeeker {
+func (o *Ole) OpenFile(file *File, root *File) io.ReadSeeker {
 	if file.Size < o.header.Sectorcutoff {
-		return o.short_stream_read(file.Sstart, file.Size)
+		return o.short_stream_read(file.Sstart, file.Size, root.Sstart)
 	} else {
 		return o.stream_read(file.Sstart, file.Size)
 	}
@@ -120,11 +120,12 @@ func (o *Ole) readMSAT() error {
 }
 
 func (o *Ole) stream_read(sid uint32, size uint32) *StreamReader {
-	return &StreamReader{o.SecID, sid, o, sid, 0, o.Lsector, int64(size), 0}
+	return &StreamReader{o.SecID, sid, o.reader, sid, 0, o.Lsector, int64(size), 0, sector_pos}
 }
 
-func (o *Ole) short_stream_read(sid uint32, size uint32) *StreamReader {
-	return &StreamReader{o.SSecID, sid, o, sid, 0, o.Lssector, int64(size), 0}
+func (o *Ole) short_stream_read(sid uint32, size uint32, startSecId uint32) *StreamReader {
+	ssatReader := &StreamReader{o.SecID, startSecId, o.reader, sid, 0, o.Lsector, int64(uint32(len(o.SSecID)) * o.Lssector), 0, sector_pos}
+	return &StreamReader{o.SSecID, sid, ssatReader, sid, 0, o.Lssector, int64(size), 0, short_sector_pos}
 }
 
 func (o *Ole) sector_read(sid uint32) (Sector, error) {
@@ -136,7 +137,7 @@ func (o *Ole) short_sector_read(sid uint32) (Sector, error) {
 }
 
 func (o *Ole) sector_read_internal(sid, size uint32) (Sector, error) {
-	pos := o.sector_pos(sid, size)
+	pos := sector_pos(sid, size)
 	if _, err := o.reader.Seek(int64(pos), 0); err == nil {
 		var bts = make([]byte, size)
 		o.reader.Read(bts)
@@ -146,6 +147,10 @@ func (o *Ole) sector_read_internal(sid, size uint32) (Sector, error) {
 	}
 }
 
-func (o *Ole) sector_pos(sid uint32, size uint32) uint32 {
+func sector_pos(sid uint32, size uint32) uint32 {
 	return 512 + sid*size
 }
+
+func short_sector_pos(sid uint32, size uint32) uint32 {
+	return sid * size
+}
diff --git a/stream_reader.go b/stream_reader.go
index a26bd93..28a9562 100644
--- a/stream_reader.go
+++ b/stream_reader.go
@@ -10,23 +10,24 @@ var DEBUG = false
 type StreamReader struct {
 	sat              []uint32
 	start            uint32
-	ole              *Ole
+	reader           io.ReadSeeker
 	offset_of_sector uint32
 	offset_in_sector uint32
 	size_sector      uint32
 	size             int64
 	offset           int64
+	sector_pos       func(uint32, uint32) uint32
 }
 
 func (r *StreamReader) Read(p []byte) (n int, err error) {
 	if r.offset_of_sector == ENDOFCHAIN {
 		return 0, io.EOF
 	}
-	pos := r.ole.sector_pos(r.offset_of_sector, r.size_sector) + r.offset_in_sector
-	r.ole.reader.Seek(int64(pos), 0)
+	pos := r.sector_pos(r.offset_of_sector, r.size_sector) + r.offset_in_sector
+	r.reader.Seek(int64(pos), 0)
 	readed := uint32(0)
 	for remainLen := uint32(len(p)) - readed; remainLen > r.size_sector-r.offset_in_sector; remainLen = uint32(len(p)) - readed {
-		if n, err := r.ole.reader.Read(p[readed : readed+r.size_sector-r.offset_in_sector]); err != nil {
+		if n, err := r.reader.Read(p[readed : readed+r.size_sector-r.offset_in_sector]); err != nil {
 			return int(readed) + n, err
 		} else {
 			readed += uint32(n)
@@ -43,11 +44,11 @@ func (r *StreamReader) Read(p []byte) (n int, err error) {
 			if r.offset_of_sector == ENDOFCHAIN {
 				return int(readed), io.EOF
 			}
-			pos := r.ole.sector_pos(r.offset_of_sector, r.size_sector) + r.offset_in_sector
-			r.ole.reader.Seek(int64(pos), 0)
+			pos := r.sector_pos(r.offset_of_sector, r.size_sector) + r.offset_in_sector
+			r.reader.Seek(int64(pos), 0)
 		}
 	}
-	if n, err := r.ole.reader.Read(p[readed:len(p)]); err == nil {
+	if n, err := r.reader.Read(p[readed:len(p)]); err == nil {
 		r.offset_in_sector += uint32(n)
 		if DEBUG {
 			log.Printf("pos:%x,bit:% X", r.offset_of_sector, p)