Dump: add output format tar and output to stdout (#10376)

* Dump: Use mholt/archive/v3 to support tar including many compressions

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: Allow dump output to stdout

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: Fixed bug present since #6677 where SessionConfig.Provider is never "file"

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: never pack RepoRootPath, LFS.ContentPath and LogRootPath when they are below AppDataPath

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: also dump LFS (fixes #10058)

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Dump: never dump CustomPath if CustomPath is a subdir of or equal to AppDataPath (fixes #10365)

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* Use log.Info instead of fmt.Fprintf

Signed-off-by: Philipp Homann <homann.philipp@googlemail.com>

* import ordering

* make fmt

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Matti R <matti@mdranta.net>

vendor/github.com/nwaples/rardecode/bit_reader.go

@@ -0,0 +1,119 @@
+package rardecode
+
+import "io"
+
+type bitReader interface {
+	readBits(n uint) (int, error) // read n bits of data
+	unreadBits(n uint)            // revert the reading of the last n bits read
+}
+
+type limitedBitReader struct {
+	br  bitReader
+	n   int
+	err error // error to return if br returns EOF before all n bits have been read
+}
+
+// limitBitReader returns a bitReader that reads from br and stops with io.EOF after n bits.
+// If br returns an io.EOF before reading n bits, err is returned.
+func limitBitReader(br bitReader, n int, err error) bitReader {
+	return &limitedBitReader{br, n, err}
+}
+
+func (l *limitedBitReader) readBits(n uint) (int, error) {
+	if int(n) > l.n {
+		return 0, io.EOF
+	}
+	v, err := l.br.readBits(n)
+	if err == nil {
+		l.n -= int(n)
+	} else if err == io.EOF {
+		err = l.err
+	}
+	return v, err
+}
+
+func (l *limitedBitReader) unreadBits(n uint) {
+	l.n += int(n)
+	l.br.unreadBits(n)
+}
+
+// rarBitReader wraps an io.ByteReader to perform various bit and byte
+// reading utility functions used in RAR file processing.
+type rarBitReader struct {
+	r io.ByteReader
+	v int
+	n uint
+}
+
+func (r *rarBitReader) reset(br io.ByteReader) {
+	r.r = br
+	r.n = 0
+	r.v = 0
+}
+
+func (r *rarBitReader) readBits(n uint) (int, error) {
+	for n > r.n {
+		c, err := r.r.ReadByte()
+		if err != nil {
+			return 0, err
+		}
+		r.v = r.v<<8 | int(c)
+		r.n += 8
+	}
+	r.n -= n
+	return (r.v >> r.n) & ((1 << n) - 1), nil
+}
+
+func (r *rarBitReader) unreadBits(n uint) {
+	r.n += n
+}
+
+// alignByte aligns the current bit reading input to the next byte boundary.
+func (r *rarBitReader) alignByte() {
+	r.n -= r.n % 8
+}
+
+// readUint32 reads a RAR V3 encoded uint32
+func (r *rarBitReader) readUint32() (uint32, error) {
+	n, err := r.readBits(2)
+	if err != nil {
+		return 0, err
+	}
+	if n != 1 {
+		n, err = r.readBits(4 << uint(n))
+		return uint32(n), err
+	}
+	n, err = r.readBits(4)
+	if err != nil {
+		return 0, err
+	}
+	if n == 0 {
+		n, err = r.readBits(8)
+		n |= -1 << 8
+		return uint32(n), err
+	}
+	nlow, err := r.readBits(4)
+	n = n<<4 | nlow
+	return uint32(n), err
+}
+
+func (r *rarBitReader) ReadByte() (byte, error) {
+	n, err := r.readBits(8)
+	return byte(n), err
+}
+
+// readFull reads len(p) bytes into p. If fewer bytes are read an error is returned.
+func (r *rarBitReader) readFull(p []byte) error {
+	for i := range p {
+		c, err := r.ReadByte()
+		if err != nil {
+			return err
+		}
+		p[i] = c
+	}
+	return nil
+}
+
+func newRarBitReader(r io.ByteReader) *rarBitReader {
+	return &rarBitReader{r: r}
+}