Rob Landley's new micro-bunzip version 3. Rob writes:

The API for using partial writes, as described in my last message, sucked.

So here's a patch against my last patch that changes things so that
write_bunzip_data calls read_bunzip_data itself behind the scenes whenever
necessary.  So usage is now just start_bunzip(), write_bunzip_data() until it
returns a negative number, and then the cleanup at the end of
uncompressStream.

It adds 32 bytes to the executable, but it should allow the caller (tar) to be
simplified enough to compensate.  Total -Os stripped exe size now 6856 bytes.

Rob

P.S.  I attached the whole C file so you don't have to keep incremental
patches straight if you don't want to. :)

P.S.  In the version I'm banging on now, I've simplified the license to just
LGPL.  I read the OSL a bit more closely and the patent termination clause
would have bit IBM in their counter-suit of SCO if the code in question had
been OSL instead of GPL, and I've decided I just don't want to beta-test
legal code right now.

1 files changed, 465 insertions, 1592 deletions

diff --git a/archival/libunarchive/decompress_bunzip2.c b/archival/libunarchive/decompress_bunzip2.c
index 0164b77e0..474186a2a 100644
--- a/archival/libunarchive/decompress_bunzip2.c
+++ b/archival/libunarchive/decompress_bunzip2.c
@@ -1,1658 +1,531 @@
-/*--
-  This file is a part of bzip2 and/or libbzip2, a program and
-  library for lossless, block-sorting data compression.
+/* vi: set sw=4 ts=4: */
+/*	Small bzip2 deflate implementation, by Rob Landley (rob@landley.net).
 
-  Copyright (C) 1996-2000 Julian R Seward.  All rights reserved.
+	Based on bzip2 decompression code by Julian R Seward (jseward@acm.org),
+	which also acknowledges contributions by Mike Burrows, David Wheeler,
+	Peter Fenwick, Alistair Moffat, Radford Neal, Ian H. Witten,
+	Robert Sedgewick, and Jon L. Bentley.
 
-  Redistribution and use in source and binary forms, with or without
-  modification, are permitted provided that the following conditions
-  are met:
+	This code is licensed under the LGPLv2:
+		LGPL (http://www.gnu.org/copyleft/lgpl.html
+*/
 
-  1. Redistributions of source code must retain the above copyright
-     notice, this list of conditions and the following disclaimer.
-
-  2. The origin of this software must not be misrepresented; you must 
-     not claim that you wrote the original software.  If you use this 
-     software in a product, an acknowledgment in the product 
-     documentation would be appreciated but is not required.
-
-  3. Altered source versions must be plainly marked as such, and must
-     not be misrepresented as being the original software.
-
-  4. The name of the author may not be used to endorse or promote 
-     products derived from this software without specific prior written 
-     permission.
-
-  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
-  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
-  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
-  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-  Julian Seward, Cambridge, UK.
-  jseward@acm.org
-  bzip2/libbzip2 version 1.0 of 21 March 2000
-
-  This program is based on (at least) the work of:
-     Mike Burrows
-     David Wheeler
-     Peter Fenwick
-     Alistair Moffat
-     Radford Neal
-     Ian H. Witten
-     Robert Sedgewick
-     Jon L. Bentley
-
-  For more information on these sources, see the manual.
---*/
-
-#include <stdlib.h>
+#include <setjmp.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
-#include <getopt.h>
 #include <unistd.h>
 
-#include "busybox.h"
-
-#define MTFA_SIZE 4096
-#define MTFL_SIZE 16
-#define BZ_N_GROUPS 6
-#define BZ_G_SIZE   50
-#define BZ_MAX_ALPHA_SIZE 258
-
-#define BZ_OK                0
-#define BZ_STREAM_END        4
-#define BZ_SEQUENCE_ERROR    (-1)
-#define BZ_DATA_ERROR        (-4)
-#define BZ_DATA_ERROR_MAGIC  (-5)
-#define BZ_IO_ERROR          (-6)
-#define BZ_UNEXPECTED_EOF    (-7)
-
-#define BZ_RUNA 0
-#define BZ_RUNB 1
-
-#define BZ_MAX_UNUSED 5000
-#define FILE_NAME_LEN 1034
-/*-- states for decompression. --*/
-
-#define BZ_X_IDLE        1
-#define BZ_X_OUTPUT      2
-
-#define BZ_X_MAGIC_1     10
-#define BZ_X_MAGIC_2     11
-#define BZ_X_MAGIC_3     12
-#define BZ_X_MAGIC_4     13
-#define BZ_X_BLKHDR_1    14
-#define BZ_X_BLKHDR_2    15
-#define BZ_X_BLKHDR_3    16
-#define BZ_X_BLKHDR_4    17
-#define BZ_X_BLKHDR_5    18
-#define BZ_X_BLKHDR_6    19
-#define BZ_X_BCRC_1      20
-#define BZ_X_BCRC_2      21
-#define BZ_X_BCRC_3      22
-#define BZ_X_BCRC_4      23
-#define BZ_X_RANDBIT     24
-#define BZ_X_ORIGPTR_1   25
-#define BZ_X_ORIGPTR_2   26
-#define BZ_X_ORIGPTR_3   27
-#define BZ_X_MAPPING_1   28
-#define BZ_X_MAPPING_2   29
-#define BZ_X_SELECTOR_1  30
-#define BZ_X_SELECTOR_2  31
-#define BZ_X_SELECTOR_3  32
-#define BZ_X_CODING_1    33
-#define BZ_X_CODING_2    34
-#define BZ_X_CODING_3    35
-#define BZ_X_MTF_1       36
-#define BZ_X_MTF_2       37
-#define BZ_X_MTF_3       38
-#define BZ_X_MTF_4       39
-#define BZ_X_MTF_5       40
-#define BZ_X_MTF_6       41
-#define BZ_X_ENDHDR_2    42
-#define BZ_X_ENDHDR_3    43
-#define BZ_X_ENDHDR_4    44
-#define BZ_X_ENDHDR_5    45
-#define BZ_X_ENDHDR_6    46
-#define BZ_X_CCRC_1      47
-#define BZ_X_CCRC_2      48
-#define BZ_X_CCRC_3      49
-#define BZ_X_CCRC_4      50
-
-#define BZ_MAX_CODE_LEN    23
-#define OM_TEST          3
-
-typedef struct {
-	char *next_in;
-	unsigned int avail_in;
-
-	char *next_out;
-	unsigned int avail_out;
-
-	void *state;
-
-} bz_stream;
-
-#define BZ_MAX_UNUSED 5000
-typedef struct {
-	bz_stream	strm;
-	int			fd;
-    unsigned char	initialisedOk;
-	char	buf[BZ_MAX_UNUSED];
-	int		lastErr;
-	int		bufN;
-} bzFile;
-
-/*-- Structure holding all the decompression-side stuff. --*/
-typedef struct {
-	/* pointer back to the struct bz_stream */
-	bz_stream* strm;
-
-	/* state indicator for this stream */
-	int	state;
-
-	/* for doing the final run-length decoding */
-	unsigned char    state_out_ch;
-	int    state_out_len;
-	unsigned char     blockRandomised;
-	int rNToGo;
-	int rTPos;
-
-	/* the buffer for bit stream reading */
-	unsigned int   bsBuff;
-	int    bsLive;
-
-	/* misc administratium */
-	int    blockSize100k;
-	int    currBlockNo;
-
-	/* for undoing the Burrows-Wheeler transform */
-	int    origPtr;
-	unsigned int   tPos;
-	int    k0;
-	int    unzftab[256];
-	int    nblock_used;
-	int    cftab[257];
-	int    cftabCopy[257];
-
-	/* for undoing the Burrows-Wheeler transform (FAST) */
-	unsigned int *tt;
-
-	/* stored and calculated CRCs */
-	unsigned int   storedBlockCRC;
-	unsigned int   storedCombinedCRC;
-	unsigned int   calculatedBlockCRC;
-	unsigned int   calculatedCombinedCRC;
-
-	/* map of bytes used in block */
-	int    nInUse;
-	unsigned char     inUse[256];
-	unsigned char     inUse16[16];
-	unsigned char    seqToUnseq[256];
-
-	/* for decoding the MTF values */
-	unsigned char    mtfa   [MTFA_SIZE];
-	unsigned char    selector   [2 + (900000 / BZ_G_SIZE)];
-	unsigned char    selectorMtf[2 + (900000 / BZ_G_SIZE)];
-	unsigned char    len  [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
-	int    mtfbase[256 / MTFL_SIZE];
-
-	int    limit  [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
-	int    base   [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
-	int    perm   [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
-	int    minLens[BZ_N_GROUPS];
-
-	/* save area for scalars in the main decompress code */
-	int    save_i;
-	int    save_j;
-	int    save_t;
-	int    save_alphaSize;
-	int    save_nGroups;
-	int    save_nSelectors;
-	int    save_EOB;
-	int    save_groupNo;
-	int    save_groupPos;
-	int    save_nextSym;
-	int    save_nblockMAX;
-	int    save_nblock;
-	int    save_es;
-	int    save_N;
-	int    save_curr;
-	int    save_zt;
-	int    save_zn; 
-	int    save_zvec;
-	int    save_zj;
-	int    save_gSel;
-	int    save_gMinlen;
-	int	*save_gLimit;
-	int	*save_gBase;
-	int	*save_gPerm;
-} DState;
-
-static int BZ2_rNums[512];
-static bzFile *bzf;
-static int bzerr = BZ_OK;
-
-static const unsigned int BZ2_crc32Table[256] = {
-
-   /*-- Ugly, innit? --*/
-
-   0x00000000L, 0x04c11db7L, 0x09823b6eL, 0x0d4326d9L,
-   0x130476dcL, 0x17c56b6bL, 0x1a864db2L, 0x1e475005L,
-   0x2608edb8L, 0x22c9f00fL, 0x2f8ad6d6L, 0x2b4bcb61L,
-   0x350c9b64L, 0x31cd86d3L, 0x3c8ea00aL, 0x384fbdbdL,
-   0x4c11db70L, 0x48d0c6c7L, 0x4593e01eL, 0x4152fda9L,
-   0x5f15adacL, 0x5bd4b01bL, 0x569796c2L, 0x52568b75L,
-   0x6a1936c8L, 0x6ed82b7fL, 0x639b0da6L, 0x675a1011L,
-   0x791d4014L, 0x7ddc5da3L, 0x709f7b7aL, 0x745e66cdL,
-   0x9823b6e0L, 0x9ce2ab57L, 0x91a18d8eL, 0x95609039L,
-   0x8b27c03cL, 0x8fe6dd8bL, 0x82a5fb52L, 0x8664e6e5L,
-   0xbe2b5b58L, 0xbaea46efL, 0xb7a96036L, 0xb3687d81L,
-   0xad2f2d84L, 0xa9ee3033L, 0xa4ad16eaL, 0xa06c0b5dL,
-   0xd4326d90L, 0xd0f37027L, 0xddb056feL, 0xd9714b49L,
-   0xc7361b4cL, 0xc3f706fbL, 0xceb42022L, 0xca753d95L,
-   0xf23a8028L, 0xf6fb9d9fL, 0xfbb8bb46L, 0xff79a6f1L,
-   0xe13ef6f4L, 0xe5ffeb43L, 0xe8bccd9aL, 0xec7dd02dL,
-   0x34867077L, 0x30476dc0L, 0x3d044b19L, 0x39c556aeL,
-   0x278206abL, 0x23431b1cL, 0x2e003dc5L, 0x2ac12072L,
-   0x128e9dcfL, 0x164f8078L, 0x1b0ca6a1L, 0x1fcdbb16L,
-   0x018aeb13L, 0x054bf6a4L, 0x0808d07dL, 0x0cc9cdcaL,
-   0x7897ab07L, 0x7c56b6b0L, 0x71159069L, 0x75d48ddeL,
-   0x6b93dddbL, 0x6f52c06cL, 0x6211e6b5L, 0x66d0fb02L,
-   0x5e9f46bfL, 0x5a5e5b08L, 0x571d7dd1L, 0x53dc6066L,
-   0x4d9b3063L, 0x495a2dd4L, 0x44190b0dL, 0x40d816baL,
-   0xaca5c697L, 0xa864db20L, 0xa527fdf9L, 0xa1e6e04eL,
-   0xbfa1b04bL, 0xbb60adfcL, 0xb6238b25L, 0xb2e29692L,
-   0x8aad2b2fL, 0x8e6c3698L, 0x832f1041L, 0x87ee0df6L,
-   0x99a95df3L, 0x9d684044L, 0x902b669dL, 0x94ea7b2aL,
-   0xe0b41de7L, 0xe4750050L, 0xe9362689L, 0xedf73b3eL,
-   0xf3b06b3bL, 0xf771768cL, 0xfa325055L, 0xfef34de2L,
-   0xc6bcf05fL, 0xc27dede8L, 0xcf3ecb31L, 0xcbffd686L,
-   0xd5b88683L, 0xd1799b34L, 0xdc3abdedL, 0xd8fba05aL,
-   0x690ce0eeL, 0x6dcdfd59L, 0x608edb80L, 0x644fc637L,
-   0x7a089632L, 0x7ec98b85L, 0x738aad5cL, 0x774bb0ebL,
-   0x4f040d56L, 0x4bc510e1L, 0x46863638L, 0x42472b8fL,
-   0x5c007b8aL, 0x58c1663dL, 0x558240e4L, 0x51435d53L,
-   0x251d3b9eL, 0x21dc2629L, 0x2c9f00f0L, 0x285e1d47L,
-   0x36194d42L, 0x32d850f5L, 0x3f9b762cL, 0x3b5a6b9bL,
-   0x0315d626L, 0x07d4cb91L, 0x0a97ed48L, 0x0e56f0ffL,
-   0x1011a0faL, 0x14d0bd4dL, 0x19939b94L, 0x1d528623L,
-   0xf12f560eL, 0xf5ee4bb9L, 0xf8ad6d60L, 0xfc6c70d7L,
-   0xe22b20d2L, 0xe6ea3d65L, 0xeba91bbcL, 0xef68060bL,
-   0xd727bbb6L, 0xd3e6a601L, 0xdea580d8L, 0xda649d6fL,
-   0xc423cd6aL, 0xc0e2d0ddL, 0xcda1f604L, 0xc960ebb3L,
-   0xbd3e8d7eL, 0xb9ff90c9L, 0xb4bcb610L, 0xb07daba7L,
-   0xae3afba2L, 0xaafbe615L, 0xa7b8c0ccL, 0xa379dd7bL,
-   0x9b3660c6L, 0x9ff77d71L, 0x92b45ba8L, 0x9675461fL,
-   0x8832161aL, 0x8cf30badL, 0x81b02d74L, 0x857130c3L,
-   0x5d8a9099L, 0x594b8d2eL, 0x5408abf7L, 0x50c9b640L,
-   0x4e8ee645L, 0x4a4ffbf2L, 0x470cdd2bL, 0x43cdc09cL,
-   0x7b827d21L, 0x7f436096L, 0x7200464fL, 0x76c15bf8L,
-   0x68860bfdL, 0x6c47164aL, 0x61043093L, 0x65c52d24L,
-   0x119b4be9L, 0x155a565eL, 0x18197087L, 0x1cd86d30L,
-   0x029f3d35L, 0x065e2082L, 0x0b1d065bL, 0x0fdc1becL,
-   0x3793a651L, 0x3352bbe6L, 0x3e119d3fL, 0x3ad08088L,
-   0x2497d08dL, 0x2056cd3aL, 0x2d15ebe3L, 0x29d4f654L,
-   0xc5a92679L, 0xc1683bceL, 0xcc2b1d17L, 0xc8ea00a0L,
-   0xd6ad50a5L, 0xd26c4d12L, 0xdf2f6bcbL, 0xdbee767cL,
-   0xe3a1cbc1L, 0xe760d676L, 0xea23f0afL, 0xeee2ed18L,
-   0xf0a5bd1dL, 0xf464a0aaL, 0xf9278673L, 0xfde69bc4L,
-   0x89b8fd09L, 0x8d79e0beL, 0x803ac667L, 0x84fbdbd0L,
-   0x9abc8bd5L, 0x9e7d9662L, 0x933eb0bbL, 0x97ffad0cL,
-   0xafb010b1L, 0xab710d06L, 0xa6322bdfL, 0xa2f33668L,
-   0xbcb4666dL, 0xb8757bdaL, 0xb5365d03L, 0xb1f740b4L
+/* Constants for huffman coding */
+#define MAX_GROUPS			6
+#define GROUP_SIZE   		50		/* 64 would have been more efficient */
+#define MAX_HUFCODE_BITS 	20		/* Longest huffman code allowed */
+#define MAX_SYMBOLS 		258		/* 256 literals + RUNA + RUNB */
+#define SYMBOL_RUNA			0
+#define SYMBOL_RUNB			1
+
+/* Status return values */
+#define RETVAL_OK						0
+#define RETVAL_LAST_BLOCK				(-1)
+#define RETVAL_NOT_BZIP_DATA			(-2)
+#define RETVAL_UNEXPECTED_INPUT_EOF		(-3)
+#define RETVAL_UNEXPECTED_OUTPUT_EOF	(-4)
+#define RETVAL_DATA_ERROR				(-5)
+#define RETVAL_OUT_OF_MEMORY			(-6)
+#define RETVAL_OBSOLETE_INPUT			(-7)
+
+/* Other housekeeping constants */
+#define IOBUF_SIZE			4096
+
+char *bunzip_errors[]={NULL,"Bad file checksum","Not bzip data",
+		"Unexpected input EOF","Unexpected output EOF","Data error",
+		 "Out of memory","Obsolete (pre 0.9.5) bzip format not supported."};
+
+/* This is what we know about each huffman coding group */
+struct group_data {
+	int limit[MAX_HUFCODE_BITS],base[MAX_HUFCODE_BITS],permute[MAX_SYMBOLS];
+	char minLen, maxLen;
 };
 
-static void bz_rand_udp_mask(DState *s)
+/* Structure holding all the housekeeping data, including IO buffers and
+   memory that persists between calls to bunzip */
+typedef struct {
+	/* For I/O error handling */
+	jmp_buf jmpbuf;
+	/* Input stream, input buffer, input bit buffer */
+	int in_fd,inbufCount,inbufPos;
+	unsigned char *inbuf;
+	unsigned int inbufBitCount, inbufBits;
+	/* Output buffer */
+	char outbuf[IOBUF_SIZE];
+	int outbufPos;
+	/* The CRC values stored in the block header and calculated from the data */
+	unsigned int crc32Table[256],headerCRC, dataCRC, totalCRC;
+	/* Intermediate buffer and its size (in bytes) */
+	unsigned int *dbuf, dbufSize;
+	/* State for interrupting output loop */
+	int writePos,writeRun,writeCount,writeCurrent;
+
+	/* These things are a bit too big to go on the stack */
+	unsigned char selectors[32768];			/* nSelectors=15 bits */
+	struct group_data groups[MAX_GROUPS];	/* huffman coding tables */
+} bunzip_data;
+
+/* Return the next nnn bits of input.  All reads from the compressed input
+   are done through this function.  All reads are big endian */
+static unsigned int get_bits(bunzip_data *bd, char bits_wanted)
 {
-	if (s->rNToGo == 0) {
-		s->rNToGo = BZ2_rNums[s->rTPos];
-		s->rTPos++;
-		if (s->rTPos == 512) {
-			s->rTPos = 0;
+	unsigned int bits=0;
+
+	/* If we need to get more data from the byte buffer, do so.  (Loop getting
+	   one byte at a time to enforce endianness and avoid unaligned access.) */
+	while (bd->inbufBitCount<bits_wanted) {
+		/* If we need to read more data from file into byte buffer, do so */
+		if(bd->inbufPos==bd->inbufCount) {
+			if(!(bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE)))
+				longjmp(bd->jmpbuf,RETVAL_UNEXPECTED_INPUT_EOF);
+			bd->inbufPos=0;
 		}
-	}
-	s->rNToGo--;
-}
-
-static void BZ2_hbCreateDecodeTables(int *limit, int *base, int *perm, unsigned char *length, int minLen, int maxLen, int alphaSize )
-{
-	int pp, i, j, vec;
-
-	pp = 0;
-	for (i = minLen; i <= maxLen; i++) {
-		for (j = 0; j < alphaSize; j++) {
-			if (length[j] == i) {
-				perm[pp] = j;
-				pp++;
-			}
+		/* Avoid 32-bit overflow (dump bit buffer to top of output) */
+		if(bd->inbufBitCount>=24) {
+			bits=bd->inbufBits&((1<<bd->inbufBitCount)-1);
+			bits_wanted-=bd->inbufBitCount;
+			bits<<=bits_wanted;
+			bd->inbufBitCount=0;
 		}
+		/* Grab next 8 bits of input from buffer. */
+		bd->inbufBits=(bd->inbufBits<<8)|bd->inbuf[bd->inbufPos++];
+		bd->inbufBitCount+=8;
 	}
+	/* Calculate result */
+	bd->inbufBitCount-=bits_wanted;
+	bits|=(bd->inbufBits>>bd->inbufBitCount)&((1<<bits_wanted)-1);
 
-	for (i = 0; i < BZ_MAX_CODE_LEN; i++) {
-		base[i] = 0;
-	}
-
-	for (i = 0; i < alphaSize; i++) {
-		base[length[i]+1]++;
-	}
-
-	for (i = 1; i < BZ_MAX_CODE_LEN; i++) {
-		base[i] += base[i-1];
-	}
-
-	for (i = 0; i < BZ_MAX_CODE_LEN; i++) {
-		limit[i] = 0;
-	}
-	vec = 0;
-
-	for (i = minLen; i <= maxLen; i++) {
-		vec += (base[i+1] - base[i]);
-		limit[i] = vec-1;
-		vec <<= 1;
-	}
-	for (i = minLen + 1; i <= maxLen; i++) {
-		base[i] = ((limit[i-1] + 1) << 1) - base[i];
-	}
-}
-
-
-static int get_bits(DState *s, int *vvv, char nnn)
-{
-	while (1) {
-		if (s->bsLive >= nnn) {
-			*vvv = (s->bsBuff >> (s->bsLive-nnn)) & ((1 << nnn)-1);
-			s->bsLive -= nnn;
-			break;
-		}
-		if (s->strm->avail_in == 0) {
-			return(FALSE);
-		}
-		s->bsBuff = (s->bsBuff << 8) | ((unsigned int) (*((unsigned char*)(s->strm->next_in))));
-		s->bsLive += 8;
-		s->strm->next_in++;
-		s->strm->avail_in--;
-	}
-	return(TRUE);
+	return bits;
 }
 
-static int bz_get_fast(DState *s)
-{
-	int cccc;
-	s->tPos = s->tt[s->tPos];
-	cccc = (unsigned char)(s->tPos & 0xff);
-	s->tPos >>= 8;
-	return(cccc);
-}
+/* Decompress a block of text to into intermediate buffer */
 
-/*---------------------------------------------------*/
-static inline int BZ2_decompress(DState *s)
+extern int read_bunzip_data(bunzip_data *bd)
 {
-	int uc = 0;
-	int	retVal;
-	int	minLen,	maxLen;
-
-	/* stuff that needs to be saved/restored */
-	int  i;
-	int  j;
-	int  t;
-	int  alphaSize;
-	int  nGroups;
-	int  nSelectors;
-	int  EOB;
-	int  groupNo;
-	int  groupPos;
-	int  nextSym;
-	int  nblockMAX;
-	int  nblock;
-	int  es;
-	int  N;
-	int  curr;
-	int  zt;
-	int  zn; 
-	int  zvec;
-	int  zj;
-	int  gSel;
-	int  gMinlen;
-	int *gLimit;
-	int *gBase;
-	int *gPerm;
-	int switch_val;
-
-	int get_mtf_val_init(void)
-	{
-		if (groupPos == 0) {
-			groupNo++;
-			if (groupNo >= nSelectors) {
-				retVal = BZ_DATA_ERROR;
-				return(FALSE);
-			}
-			groupPos = BZ_G_SIZE;
-			gSel = s->selector[groupNo];
-			gMinlen = s->minLens[gSel];
-			gLimit = &(s->limit[gSel][0]);
-			gPerm = &(s->perm[gSel][0]);
-			gBase = &(s->base[gSel][0]);
+	struct group_data *hufGroup;
+	int dbufCount,nextSym,dbufSize,origPtr,groupCount,*base,*limit,selector,
+		i,j,k,t,runPos,symCount,symTotal,nSelectors,byteCount[256];
+	unsigned char uc, symToByte[256], mtfSymbol[256], *selectors;
+	unsigned int *dbuf;
+
+	/* Read in header signature (borrowing mtfSymbol for temp space). */
+	for(i=0;i<6;i++) mtfSymbol[i]=get_bits(bd,8);
+	mtfSymbol[6]=0;
+	/* Read CRC (which is stored big endian). */
+	bd->headerCRC=get_bits(bd,32);
+	/* Is this the last block (with CRC for file)? */
+	if(!strcmp(mtfSymbol,"\x17\x72\x45\x38\x50\x90"))
+		return RETVAL_LAST_BLOCK;
+	/* If it's not a valid data block, barf. */
+	if(strcmp(mtfSymbol,"\x31\x41\x59\x26\x53\x59"))
+		return RETVAL_NOT_BZIP_DATA;
+
+	dbuf=bd->dbuf;
+	dbufSize=bd->dbufSize;
+	selectors=bd->selectors;
+	/* We can add support for blockRandomised if anybody complains.  There was
+	   some code for this in busybox 1.0.0-pre3, but nobody ever noticed that
+	   it didn't actually work. */
+	if(get_bits(bd,1)) return RETVAL_OBSOLETE_INPUT;
+	if((origPtr=get_bits(bd,24)) > dbufSize) return RETVAL_DATA_ERROR;
+	/* mapping table: if some byte values are never used (encoding things
+	   like ascii text), the compression code removes the gaps to have fewer
+	   symbols to deal with, and writes a sparse bitfield indicating which
+	   values were present.  We make a translation table to convert the symbols
+	   back to the corresponding bytes. */
+	t=get_bits(bd, 16);
+	memset(symToByte,0,256);
+	symTotal=0;
+	for (i=0;i<16;i++) {
+		if(t&(1<<(15-i))) {
+			k=get_bits(bd,16);
+			for(j=0;j<16;j++)
+				if(k&(1<<(15-j))) symToByte[symTotal++]=(16*i)+j;
 		}
-		groupPos--;
-		zn = gMinlen;
-		return(TRUE);
 	}
-
-	if (s->state == BZ_X_MAGIC_1) {
-		/*initialise the save area*/
-		s->save_i           = 0;
-		s->save_j           = 0;
-		s->save_t           = 0;
-		s->save_alphaSize   = 0;
-		s->save_nGroups     = 0;
-		s->save_nSelectors  = 0;
-		s->save_EOB         = 0;
-		s->save_groupNo     = 0;
-		s->save_groupPos    = 0;
-		s->save_nextSym     = 0;
-		s->save_nblockMAX   = 0;
-		s->save_nblock      = 0;
-		s->save_es          = 0;
-		s->save_N           = 0;
-		s->save_curr        = 0;
-		s->save_zt          = 0;
-		s->save_zn          = 0;
-		s->save_zvec        = 0;
-		s->save_zj          = 0;
-		s->save_gSel        = 0;
-		s->save_gMinlen     = 0;
-		s->save_gLimit      = NULL;
-		s->save_gBase       = NULL;
-		s->save_gPerm       = NULL;
+	/* How many different huffman coding groups does this block use? */
+	groupCount=get_bits(bd,3);
+	if (groupCount<2 || groupCount>MAX_GROUPS) return RETVAL_DATA_ERROR;
+	/* nSelectors: Every GROUP_SIZE many symbols we select a new huffman coding
+	   group.  Read in the group selector list, which is stored as MTF encoded
+	   bit runs. */
+	if(!(nSelectors=get_bits(bd, 15))) return RETVAL_DATA_ERROR;
+	for(i=0; i<groupCount; i++) mtfSymbol[i] = i;
+	for(i=0; i<nSelectors; i++) {
+		/* Get next value */
+		for(j=0;get_bits(bd,1);j++) if (j>=groupCount) return RETVAL_DATA_ERROR;
+		/* Decode MTF to get the next selector */
+		uc = mtfSymbol[j];
+		memmove(mtfSymbol+1,mtfSymbol,j);
+		mtfSymbol[0]=selectors[i]=uc;
 	}
-
-	/*restore from the save area*/
-	i           = s->save_i;
-	j           = s->save_j;
-	t           = s->save_t;
-	alphaSize   = s->save_alphaSize;
-	nGroups     = s->save_nGroups;
-	nSelectors  = s->save_nSelectors;
-	EOB         = s->save_EOB;
-	groupNo     = s->save_groupNo;
-	groupPos    = s->save_groupPos;
-	nextSym     = s->save_nextSym;
-	nblockMAX   = s->save_nblockMAX;
-	nblock      = s->save_nblock;
-	es          = s->save_es;
-	N           = s->save_N;
-	curr        = s->save_curr;
-	zt          = s->save_zt;
-	zn          = s->save_zn; 
-	zvec        = s->save_zvec;
-	zj          = s->save_zj;
-	gSel        = s->save_gSel;
-	gMinlen     = s->save_gMinlen;
-	gLimit      = s->save_gLimit;
-	gBase       = s->save_gBase;
-	gPerm       = s->save_gPerm;
-
-	retVal = BZ_OK;
-	switch_val = s->state;
-	switch (switch_val) {
-		case BZ_X_MAGIC_1:
-			s->state = BZ_X_MAGIC_1;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 'B') {
-				retVal = BZ_DATA_ERROR_MAGIC;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_MAGIC_2:
-			s->state = BZ_X_MAGIC_2;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 'Z') {
-				retVal = BZ_DATA_ERROR_MAGIC;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_MAGIC_3:
-			s->state = BZ_X_MAGIC_3;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 'h') {
-				retVal = BZ_DATA_ERROR_MAGIC;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_MAGIC_4:
-			s->state = BZ_X_MAGIC_4;
-			if (! get_bits(s, &s->blockSize100k, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if ((s->blockSize100k < '1') || (s->blockSize100k > '9')) {
-				retVal = BZ_DATA_ERROR_MAGIC;
-				goto save_state_and_return;
-			}
-			s->blockSize100k -= '0';
-
-			s->tt = xmalloc(s->blockSize100k * 100000 * sizeof(int));
-
-		case BZ_X_BLKHDR_1:
-			s->state = BZ_X_BLKHDR_1;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-
-			if (uc == 0x17) {
-				goto endhdr_2;
-			}
-			if (uc != 0x31) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_BLKHDR_2:
-			s->state = BZ_X_BLKHDR_2;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x41) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_BLKHDR_3:
-			s->state = BZ_X_BLKHDR_3;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x59) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_BLKHDR_4:
-			s->state = BZ_X_BLKHDR_4;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x26) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_BLKHDR_5:
-			s->state = BZ_X_BLKHDR_5;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x53) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_BLKHDR_6:
-			s->state = BZ_X_BLKHDR_6;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x59) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		s->currBlockNo++;
-		s->storedBlockCRC = 0;
-
-		case BZ_X_BCRC_1:
-			s->state = BZ_X_BCRC_1;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);
-
-		case BZ_X_BCRC_2:
-			s->state = BZ_X_BCRC_2;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);
-
-		case BZ_X_BCRC_3:
-			s->state = BZ_X_BCRC_3;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);
-
-		case BZ_X_BCRC_4:
-			s->state = BZ_X_BCRC_4;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);
-
-		case BZ_X_RANDBIT:
-			s->state = BZ_X_RANDBIT;
-			{
-				int tmp = s->blockRandomised;
-				const int ret = get_bits(s, &tmp, 1);
-				s->blockRandomised = tmp;
-				if (! ret) {
-					retVal = BZ_OK;
-					goto save_state_and_return;
-				}
-			}
-
-			s->origPtr = 0;
-
-		case BZ_X_ORIGPTR_1:
-			s->state = BZ_X_ORIGPTR_1;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->origPtr = (s->origPtr << 8) | ((int)uc);
-
-		case BZ_X_ORIGPTR_2:
-			s->state = BZ_X_ORIGPTR_2;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->origPtr = (s->origPtr << 8) | ((int)uc);
-
-		case BZ_X_ORIGPTR_3:
-			s->state = BZ_X_ORIGPTR_3;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->origPtr = (s->origPtr << 8) | ((int)uc);
-
-			if (s->origPtr < 0) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-			if (s->origPtr > 10 + 100000*s->blockSize100k) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-			/*--- Receive the mapping table ---*/
-		case BZ_X_MAPPING_1:
-			for (i = 0; i < 16; i++) {
-				s->state = BZ_X_MAPPING_1;
-				if (! get_bits(s, &uc, 1)) {
-					retVal = BZ_OK;
-					goto save_state_and_return;
-				}
-				if (uc == 1) {
-					s->inUse16[i] = TRUE;
-				} else {
-					s->inUse16[i] = FALSE;
-				}
-			}
-
-			for (i = 0; i < 256; i++) {
-				s->inUse[i] = FALSE;
-			}
-
-			for (i = 0; i < 16; i++) {
-				if (s->inUse16[i]) {
-					for (j = 0; j < 16; j++) {
-					case BZ_X_MAPPING_2:
-						s->state = BZ_X_MAPPING_2;
-						if (! get_bits(s, &uc, 1)) {
-							retVal = BZ_OK;
-							goto save_state_and_return;
-						}
-						if (uc == 1) {
-							s->inUse[i * 16 + j] = TRUE;
-						}
-					}
-				}
-			}
-
-			s->nInUse = 0;
-			for (i = 0; i < 256; i++) {
-				if (s->inUse[i]) {
-					s->seqToUnseq[s->nInUse] = i;
-					s->nInUse++;
-				}
-			}
-			if (s->nInUse == 0) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-			alphaSize = s->nInUse+2;
-
-		/*--- Now the selectors ---*/
-		case BZ_X_SELECTOR_1:
-			s->state = BZ_X_SELECTOR_1;
-			if (! get_bits(s, &nGroups, 3)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (nGroups < 2 || nGroups > 6) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_SELECTOR_2:
-			s->state = BZ_X_SELECTOR_2;
-			if (! get_bits(s, &nSelectors, 15)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (nSelectors < 1) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-
-
-			for (i = 0; i < nSelectors; i++) {
-				j = 0;
-				while (1) {
-					case BZ_X_SELECTOR_3:
-					s->state = BZ_X_SELECTOR_3;
-					if (! get_bits(s, &uc, 1)) {
-						retVal = BZ_OK;
-						goto save_state_and_return;
-					}
-					if (uc == 0) {
-						break;
-					}
-					j++;
-					if (j >= nGroups) {
-						retVal = BZ_DATA_ERROR;
-						goto save_state_and_return;
-					}
-				}
-				s->selectorMtf[i] = j;
-			}
-
-			/*--- Undo the MTF values for the selectors. ---*/
-			{
-				unsigned char pos[BZ_N_GROUPS], tmp, v;
-				for (v = 0; v < nGroups; v++) {
-					pos[v] = v;
-				}
-				for (i = 0; i < nSelectors; i++) {
-					v = s->selectorMtf[i];
-					tmp = pos[v];
-					while (v > 0) {
-						pos[v] = pos[v-1];
-						v--;
-					}
-					pos[0] = tmp;
-					s->selector[i] = tmp;
-				}
-			}
-
-			/*--- Now the coding tables ---*/
-			for (t = 0; t < nGroups; t++) {
-			case BZ_X_CODING_1:
-				s->state = BZ_X_CODING_1;
-				if (! get_bits(s, &curr, 5)) {
-					retVal = BZ_OK;
-					goto save_state_and_return;
-				}
-			for (i = 0; i < alphaSize; i++) {
-				while (TRUE) {
-					if (curr < 1 || curr > 20) {
-						retVal = BZ_DATA_ERROR;
-						goto save_state_and_return;
-					}
-
-					case BZ_X_CODING_2:
-						s->state = BZ_X_CODING_2;
-						if (! get_bits(s, &uc, 1)) {
-							retVal = BZ_OK;
-							goto save_state_and_return;
-						}
-						if (uc == 0) {
-							break;
-						}
-
-					case BZ_X_CODING_3:
-						s->state = BZ_X_CODING_3;
-						if (! get_bits(s, &uc, 1)) {
-							retVal = BZ_OK;
-							goto save_state_and_return;
-						}
-						if (uc == 0) {
-							curr++;
-						} else {
-							curr--;
-						}
-				}
-				s->len[t][i] = curr;
-			}
+	/* Read the huffman coding tables for each group, which code for symTotal
+	   literal symbols, plus two run symbols (RUNA, RUNB) */
+	symCount=symTotal+2;
+	for (j=0; j<groupCount; j++) {
+		unsigned char length[MAX_SYMBOLS],temp[MAX_HUFCODE_BITS+1];
+		int	minLen,	maxLen, pp;
+		/* Read lengths */
+		t=get_bits(bd, 5);
+		for (i = 0; i < symCount; i++) {
+			for(;;) {
+				if (t < 1 || t > MAX_HUFCODE_BITS) return RETVAL_DATA_ERROR;
+					if(!get_bits(bd, 1)) break;
+					if(!get_bits(bd, 1)) t++;
+					else t--;
+			}
+			length[i] = t;
 		}
-
-		/*--- Create the Huffman decoding tables ---*/
-		for (t = 0; t < nGroups; t++) {
-			minLen = 32;
-			maxLen = 0;
-			for (i = 0; i < alphaSize; i++) {
-				if (s->len[t][i] > maxLen) {
-					maxLen = s->len[t][i];
-				}
-				if (s->len[t][i] < minLen) {
-					minLen = s->len[t][i];
-				}
-			}
-
-			BZ2_hbCreateDecodeTables ( 
-				&(s->limit[t][0]), 
-				&(s->base[t][0]), 
-				&(s->perm[t][0]), 
-				&(s->len[t][0]),
-				minLen, maxLen, alphaSize
-				);
-
-
-			s->minLens[t] = minLen;
+		/* Find largest and smallest lengths in this group */
+		minLen=maxLen=length[0];
+		for(i = 1; i < symCount; i++) {
+			if(length[i] > maxLen) maxLen = length[i];
+			else if(length[i] < minLen) minLen = length[i];
 		}
-
-		/*--- Now the MTF values ---*/
-
-		EOB      = s->nInUse+1;
-		nblockMAX = 100000 * s->blockSize100k;
-		groupNo  = -1;
-		groupPos = 0;
-
-		for (i = 0; i <= 255; i++) {
-			s->unzftab[i] = 0;
+		/* Calculate permute[], base[], and limit[] tables from length[].
+		 *
+		 * permute[] is the lookup table for converting huffman coded symbols
+		 * into decoded symbols.  base[] is the amount to subtract from the
+		 * value of a huffman symbol of a given length when using permute[].
+		 *
+		 * limit[] indicates the largest numerical value a symbol with a given
+		 * number of bits can have.  It lets us know when to stop reading.
+		 *
+		 * To use these, keep reading bits until value<=limit[bitcount] or
+		 * you've read over 20 bits (error).  Then the decoded symbol
+		 * equals permute[hufcode_value-base[hufcode_bitcount]].
+		 */
+		hufGroup=bd->groups+j;
+		hufGroup->minLen = minLen;
+		hufGroup->maxLen = maxLen;
+		/* Note that minLen can't be smaller than 1, so we adjust the base
+		   and limit array pointers so we're not always wasting the first
+		   entry.  We do this again when using them (during symbol decoding).*/
+		base=hufGroup->base-1;
+		limit=hufGroup->limit-1;
+		/* Calculate permute[] */
+		pp = 0;
+		for(i=minLen;i<=maxLen;i++) 
+			for(t=0;t<symCount;t++) 
+				if(length[t]==i) hufGroup->permute[pp++] = t;
+		/* Count cumulative symbols coded for at each bit length */
+		for (i=minLen;i<=maxLen;i++) temp[i]=limit[i]=0;
+		for (i=0;i<symCount;i++) temp[length[i]]++;
+		/* Calculate limit[] (the largest symbol-coding value at each bit
+		 * length, which is (previous limit<<1)+symbols at this level), and
+		 * base[] (number of symbols to ignore at each bit length, which is
+		 * limit-cumulative count of symbols coded for already). */
+		pp=t=0;
+		for (i=minLen; i<maxLen; i++) {
+			pp+=temp[i];
+			limit[i]=pp-1;
+			pp<<=1;
+			base[i+1]=pp-(t+=temp[i]);
 		}
-		/*-- MTF init --*/
-		{
-			int ii, jj, kk;
-			kk = MTFA_SIZE-1;
-			for (ii = 256 / MTFL_SIZE - 1; ii >= 0; ii--) {
-				for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
-					s->mtfa[kk] = (unsigned char)(ii * MTFL_SIZE + jj);
-					kk--;
-				}
-				s->mtfbase[ii] = kk + 1;
-			}
+		limit[maxLen]=pp+temp[maxLen]-1;
+		base[minLen]=0;
+	}
+	/* We've finished reading and digesting the block header.  Now read this
+	   block's huffman coded symbols from the file and undo the huffman coding
+	   and run length encoding, saving the result into dbuf[dbufCount++]=uc */
+
+	/* Initialize symbol occurrence counters and symbol mtf table */
+	memset(byteCount,0,256*sizeof(int));
+	for(i=0;i<256;i++) mtfSymbol[i]=(unsigned char)i;
+	/* Loop through compressed symbols */
+	runPos=dbufCount=symCount=selector=0;
+	for(;;) {
+		/* Determine which huffman coding group to use. */
+		if(!(symCount--)) {
+			symCount=GROUP_SIZE-1;
+			if(selector>=nSelectors) return RETVAL_DATA_ERROR;
+			hufGroup=bd->groups+selectors[selector++];
+			base=hufGroup->base-1;
+			limit=hufGroup->limit-1;
 		}
-		/*-- end MTF init --*/
-
-		nblock = 0;
-
-		if (! get_mtf_val_init()) {
-			goto save_state_and_return;
+		/* Read next huffman-coded symbol */
+		i = hufGroup->minLen;
+		j=get_bits(bd, i);
+		for(;;) {
+			if (i > hufGroup->maxLen) return RETVAL_DATA_ERROR;
+			if (j <= limit[i]) break;
+			i++;
+
+			j = (j << 1) | get_bits(bd,1);
 		}
-		case BZ_X_MTF_1:
-			s->state = BZ_X_MTF_1;
-			if (! get_bits(s, &zvec, zn)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			while (1) {
-				if (zn > 20 /* the longest code */) {
-					retVal = BZ_DATA_ERROR;
-					goto save_state_and_return;
-				}
-				if (zvec <= gLimit[zn]) {
-					break;
-				}
-				zn++;
-
-				case BZ_X_MTF_2:
-					s->state = BZ_X_MTF_2;
-					if (! get_bits(s, &zj, 1)) {
-						retVal = BZ_OK;
-						goto save_state_and_return;
-					}
-					zvec = (zvec << 1) | zj;
-			}
-			if (zvec - gBase[zn] < 0 || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-			nextSym = gPerm[zvec - gBase[zn]];
-
-		while (1) {
-			if (nextSym == EOB) {
-				break;
-			}
-
-		if (nextSym == BZ_RUNA || nextSym == BZ_RUNB) {
-			es = -1;
-			N = 1;
-			do {
-				if (nextSym == BZ_RUNA) {
-					es = es + (0+1) * N;
-				} else {
-					if (nextSym == BZ_RUNB) {
-						es = es + (1+1) * N;
-					}
-				}
-				N = N * 2;
-				if (! get_mtf_val_init()) {
-					goto save_state_and_return;
-				}
-				case BZ_X_MTF_3:
-					s->state = BZ_X_MTF_3;
-					if (! get_bits(s, &zvec, zn)) {
-						retVal = BZ_OK;
-						goto save_state_and_return;
-					}
-					while (1) {
-						if (zn > 20 /* the longest code */) {
-							retVal = BZ_DATA_ERROR;
-							goto save_state_and_return;
-						}
-						if (zvec <= gLimit[zn]) {
-							break;
-						}
-						zn++;
-
-						case BZ_X_MTF_4:
-							s->state = BZ_X_MTF_4;
-							if (! get_bits(s, &zj, 1)) {
-								retVal = BZ_OK;
-								goto save_state_and_return;
-							}
-							zvec = (zvec << 1) | zj;
-					}
-					if (zvec - gBase[zn] < 0 || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE) {
-						retVal = BZ_DATA_ERROR;
-						goto save_state_and_return;
-
-					}
-					nextSym = gPerm[zvec - gBase[zn]];
-			}
-			while (nextSym == BZ_RUNA || nextSym == BZ_RUNB);
-
-			es++;
-			uc = s->seqToUnseq[ s->mtfa[s->mtfbase[0]] ];
-			s->unzftab[uc] += es;
-
-			while (es > 0) {
-				if (nblock >= nblockMAX) {
-					retVal = BZ_DATA_ERROR;
-					goto save_state_and_return;
-				}
-				s->tt[nblock] = (unsigned int)uc;
-				nblock++;
-				es--;
-			}
-			continue;
-		} else {
-			if (nblock >= nblockMAX) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-			/*-- uc = MTF ( nextSym-1 ) --*/
-			{
-				int ii, jj, kk, pp, lno, off;
-				unsigned int nn;
-				nn = (unsigned int)(nextSym - 1);
-
-				if (nn < MTFL_SIZE) {
-					/* avoid general-case expense */
-					pp = s->mtfbase[0];
-					uc = s->mtfa[pp+nn];
-					while (nn > 3) {
-						int z = pp+nn;
-						s->mtfa[(z)  ] = s->mtfa[(z)-1];
-						s->mtfa[(z)-1] = s->mtfa[(z)-2];
-						s->mtfa[(z)-2] = s->mtfa[(z)-3];
-						s->mtfa[(z)-3] = s->mtfa[(z)-4];
-						nn -= 4;
-					}
-					while (nn > 0) { 
-						s->mtfa[(pp+nn)] = s->mtfa[(pp+nn)-1]; nn--; 
-					}
-					s->mtfa[pp] = uc;
-				} else { 
-					/* general case */
-					lno = nn / MTFL_SIZE;
-					off = nn % MTFL_SIZE;
-					pp = s->mtfbase[lno] + off;
-					uc = s->mtfa[pp];
-					while (pp > s->mtfbase[lno]) { 
-						s->mtfa[pp] = s->mtfa[pp-1];
-						pp--; 
-					}
-					s->mtfbase[lno]++;
-					while (lno > 0) {
-						s->mtfbase[lno]--;
-						s->mtfa[s->mtfbase[lno]] = s->mtfa[s->mtfbase[lno-1] + MTFL_SIZE - 1];
-						lno--;
-					}
-					s->mtfbase[0]--;
-					s->mtfa[s->mtfbase[0]] = uc;
-					if (s->mtfbase[0] == 0) {
-						kk = MTFA_SIZE-1;
-						for (ii = 256 / MTFL_SIZE-1; ii >= 0; ii--) {
-							for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
-								s->mtfa[kk] = s->mtfa[s->mtfbase[ii] + jj];
-								kk--;
-							}
-							s->mtfbase[ii] = kk + 1;
-						}
-					}
-				}
-			}
-			/*-- end uc = MTF ( nextSym-1 ) --*/
-
-			s->unzftab[s->seqToUnseq[uc]]++;
-			s->tt[nblock]   = (unsigned int)(s->seqToUnseq[uc]);
-			nblock++;
-
-			if (! get_mtf_val_init()) {
-				goto save_state_and_return;
-			}
-			case BZ_X_MTF_5:
-				s->state = BZ_X_MTF_5;
-				if (! get_bits(s, &zvec, zn)) {
-					retVal = BZ_OK;
-					goto save_state_and_return;
-				}
-				while (1) {
-					if (zn > 20 /* the longest code */) {
-						retVal = BZ_DATA_ERROR;
-						goto save_state_and_return;
-					}
-					if (zvec <= gLimit[zn]) {
-						break;
-					}
-					zn++;
-
-					case BZ_X_MTF_6:
-						s->state = BZ_X_MTF_6;
-						if (! get_bits(s, &zj, 1)) {
-							retVal = BZ_OK;
-							goto save_state_and_return;
-						}
-						zvec = (zvec << 1) | zj;
-				}
-			if (zvec - gBase[zn] < 0 || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-			nextSym = gPerm[zvec - gBase[zn]];
+		/* Huffman decode nextSym (with bounds checking) */
+		j-=base[i];
+		if (j < 0 || j >= MAX_SYMBOLS) return RETVAL_DATA_ERROR;
+		nextSym = hufGroup->permute[j];
+		/* If this is a repeated run, loop collecting data */
+		if (nextSym == SYMBOL_RUNA || nextSym == SYMBOL_RUNB) {
+			/* If this is the start of a new run, zero out counter */
+			if(!runPos) {
+				runPos = 1;
+				t = 0;
+			}
+			/* Neat trick that saves 1 symbol: instead of or-ing 0 or 1 at
+			   each bit position, add 1 or 2 instead.  For example,
+			   1011 is 1<<0 + 1<<1 + 2<<2.  1010 is 2<<0 + 2<<1 + 1<<2.
+			   You can make any bit pattern that way using 1 less symbol than
+			   the basic or 0/1 method (except all bits 0, which would use no
+			   symbols, but a run of length 0 doesn't mean anything in this
+			   context).  Thus space is saved. */
+			if (nextSym == SYMBOL_RUNA) t += runPos;
+			else t += 2*runPos;
+			runPos <<= 1;
 			continue;
 		}
+		/* When we hit the first non-run symbol after a run, we now know
+		   how many times to repeat the last literal, so append that many
+		   copies to our buffer of decoded symbols (dbuf) now.  (The last
+		   literal used is the one at the head of the mtfSymbol array.) */
+		if(runPos) {
+			runPos=0;
+			if(dbufCount+t>=dbufSize) return RETVAL_DATA_ERROR;
+
+			uc = symToByte[mtfSymbol[0]];
+			byteCount[uc] += t;
+			while(t--) dbuf[dbufCount++]=uc;
+		}
+		/* Is this the terminating symbol? */
+		if(nextSym>symTotal) break;
+		/* At this point, the symbol we just decoded indicates a new literal
+		   character.  Subtract one to get the position in the MTF array
+		   at which this literal is currently to be found.  (Note that the
+		   result can't be -1 or 0, because 0 and 1 are RUNA and RUNB.
+		   Another instance of the first symbol in the mtf array, position 0,
+		   would have been handled as part of a run.) */
+		if(dbufCount>=dbufSize) return RETVAL_DATA_ERROR;
+		i = nextSym - 1;
+		uc = mtfSymbol[i];
+		memmove(mtfSymbol+1,mtfSymbol,i);
+		mtfSymbol[0] = uc;
+		uc=symToByte[uc];
+		/* We have our literal byte.  Save it into dbuf. */
+		byteCount[uc]++;
+		dbuf[dbufCount++] = (unsigned int)uc;
 	}
-
-	/* Now we know what nblock is, we can do a better sanity
-		check on s->origPtr.
-	*/
-	if (s->origPtr < 0 || s->origPtr >= nblock) {
-		retVal = BZ_DATA_ERROR;
-		goto save_state_and_return;
+	/* At this point, we've finished reading huffman-coded symbols and
+	   compressed runs from the input stream.  There are dbufCount many of
+	   them in dbuf[].  Now undo the Burrows-Wheeler transform on dbuf.
+	   See http://dogma.net/markn/articles/bwt/bwt.htm
+	 */
+
+	/* Now we know what dbufCount is, do a better sanity check on origPtr.  */
+	if (origPtr<0 || origPtr>=dbufCount) return RETVAL_DATA_ERROR;
+	/* Turn byteCount into cumulative occurrence counts of 0 to n-1. */
+	j=0;
+	for(i=0;i<256;i++) {
+		k=j+byteCount[i];
+		byteCount[i] = j;
+		j=k;
 	}
-	s->state_out_len = 0;
-	s->state_out_ch  = 0;
-	s->calculatedBlockCRC = 0xffffffffL;
-	s->state = BZ_X_OUTPUT;
-
-	/*-- Set up cftab to facilitate generation of T^(-1) --*/
-	s->cftab[0] = 0;
-	for (i = 1; i <= 256; i++) {
-		s->cftab[i] = s->unzftab[i-1];
+	/* Figure out what order dbuf would be in if we sorted it. */
+	for (i=0;i<dbufCount;i++) {
+		uc = (unsigned char)(dbuf[i] & 0xff);
+		dbuf[byteCount[uc]] |= (i << 8);
+		byteCount[uc]++;
 	}
-	for (i = 1; i <= 256; i++) {
-		s->cftab[i] += s->cftab[i-1];
+	/* blockRandomised support would go here. */
+
+	/* Using i as position, j as previous character, t as current character,
+	   and uc as run count */
+	bd->dataCRC = 0xffffffffL;
+	/* Decode first byte by hand to initialize "previous" byte.  Note that it
+	   doesn't get output, and if the first three characters are identical
+	   it doesn't qualify as a run (hence uc=255, which will either wrap
+	   to 1 or get reset). */
+	if(dbufCount) {
+		bd->writePos=dbuf[origPtr];
+	    bd->writeCurrent=(unsigned char)(bd->writePos&0xff);
+		bd->writePos>>=8;
+		bd->writeRun=-1;
 	}
+	bd->writeCount=dbufCount;
 
-	/*-- compute the T^(-1) vector --*/
-	for (i = 0; i < nblock; i++) {
-		uc = (unsigned char)(s->tt[i] & 0xff);
-		s->tt[s->cftab[uc]] |= (i << 8);
-		s->cftab[uc]++;
-	}
-
-	s->tPos = s->tt[s->origPtr] >> 8;
-	s->nblock_used = 0;
-	if (s->blockRandomised) {
-		s->rNToGo = 0;
-		s->rTPos  = 0;
-		s->k0 = bz_get_fast(s);
-
-		s->nblock_used++;
-		bz_rand_udp_mask(s);
-		s->k0 ^= ((s->rNToGo == 1) ? 1 : 0);
-	} else {
-		s->k0 = bz_get_fast(s);
-		s->nblock_used++;
-	}
-
-		retVal = BZ_OK;
-		goto save_state_and_return;
-
-endhdr_2:
-		case BZ_X_ENDHDR_2:
-			s->state = BZ_X_ENDHDR_2;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x72) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_ENDHDR_3:
-			s->state = BZ_X_ENDHDR_3;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x45) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_ENDHDR_4:
-			s->state = BZ_X_ENDHDR_4;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x38) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_ENDHDR_5:
-			s->state = BZ_X_ENDHDR_5;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x50) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-
-		case BZ_X_ENDHDR_6:
-			s->state = BZ_X_ENDHDR_6;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			if (uc != 0x90) {
-				retVal = BZ_DATA_ERROR;
-				goto save_state_and_return;
-			}
-			s->storedCombinedCRC = 0;
-
-		case BZ_X_CCRC_1:
-			s->state = BZ_X_CCRC_1;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((unsigned int)uc);
-		case BZ_X_CCRC_2:
-			s->state = BZ_X_CCRC_2;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((unsigned int)uc);
-
-		case BZ_X_CCRC_3:
-			s->state = BZ_X_CCRC_3;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((unsigned int)uc);
-
-		case BZ_X_CCRC_4:
-			s->state = BZ_X_CCRC_4;
-			if (! get_bits(s, &uc, 8)) {
-				retVal = BZ_OK;
-				goto save_state_and_return;
-			}
-			s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((unsigned int)uc);
-
-		s->state = BZ_X_IDLE;
-		retVal = BZ_STREAM_END;
-		goto save_state_and_return;
-
-	}
-
-save_state_and_return:
-	s->save_i           = i;
-	s->save_j           = j;
-	s->save_t           = t;
-	s->save_alphaSize   = alphaSize;
-	s->save_nGroups     = nGroups;
-	s->save_nSelectors  = nSelectors;
-	s->save_EOB         = EOB;
-	s->save_groupNo     = groupNo;
-	s->save_groupPos    = groupPos;
-	s->save_nextSym     = nextSym;
-	s->save_nblockMAX   = nblockMAX;
-	s->save_nblock      = nblock;
-	s->save_es          = es;
-	s->save_N           = N;
-	s->save_curr        = curr;
-	s->save_zt          = zt;
-	s->save_zn          = zn;
-	s->save_zvec        = zvec;
-	s->save_zj          = zj;
-	s->save_gSel        = gSel;
-	s->save_gMinlen     = gMinlen;
-	s->save_gLimit      = gLimit;
-	s->save_gBase       = gBase;
-	s->save_gPerm       = gPerm;
-
-	return retVal;   
+	return RETVAL_OK;
 }
 
-extern void BZ2_bzReadClose(void)
+/* Flush output buffer to disk */
+extern void flush_bunzip_outbuf(bunzip_data *bd, int out_fd)
 {
-	if (bzf->initialisedOk) {
-		bz_stream *strm = &(bzf->strm);
-		DState *s;
-		if (strm == NULL) {
-			return;
-		}
-		s = strm->state;
-		if ((s == NULL) || (s->strm != strm)) {
-			return;
-		}
-		free(s->tt);
-		free(strm->state);
-		strm->state = NULL;
-		return;
+	if(bd->outbufPos) {
+		if(write(out_fd, bd->outbuf, bd->outbufPos) != bd->outbufPos)
+			longjmp(bd->jmpbuf,RETVAL_UNEXPECTED_OUTPUT_EOF);
+		bd->outbufPos=0;
 	}
-	free(bzf);
 }
 
-static void unRLE_obuf_to_output_FAST(DState *s)
-{
-	unsigned char k1;
-
-	if (s->blockRandomised) {
-		while (1) {
-			/* try to finish existing run */
-			while (1) {
-				if (s->strm->avail_out == 0) {
-					return;
-				}
-				if (s->state_out_len == 0) {
-					break;
-				}
-				*((unsigned char *)(s->strm->next_out)) = s->state_out_ch;
-				s->calculatedBlockCRC = (s->calculatedBlockCRC << 8) ^
-					BZ2_crc32Table[(s->calculatedBlockCRC >> 24) ^
-					((unsigned char)s->state_out_ch)];
-				s->state_out_len--;
-				s->strm->next_out++;
-				s->strm->avail_out--;
-			}
-   
-			/* can a new run be started? */
-			if (s->nblock_used == s->save_nblock+1) {
-				return;
-			}
-			s->state_out_len = 1;
-			s->state_out_ch = s->k0;
-			k1 = bz_get_fast(s);
-			bz_rand_udp_mask(s);
-			k1 ^= ((s->rNToGo == 1) ? 1 : 0);
-			s->nblock_used++;
-			if (s->nblock_used == s->save_nblock+1) {
-				continue;
-			}
-			if (k1 != s->k0) {
-				s->k0 = k1;
-				continue;
-			}
 
-			s->state_out_len = 2;
-			k1 = bz_get_fast(s);
-			bz_rand_udp_mask(s);
-			k1 ^= ((s->rNToGo == 1) ? 1 : 0);
-			s->nblock_used++;
-			if (s->nblock_used == s->save_nblock+1) {
-				continue;
-			}
-			if (k1 != s->k0) {
-				s->k0 = k1;
-				continue;
-			}
-			s->state_out_len = 3;
-			k1 = bz_get_fast(s);
-			bz_rand_udp_mask(s);
-			k1 ^= ((s->rNToGo == 1) ? 1 : 0);
-			s->nblock_used++;
-			if (s->nblock_used == s->save_nblock+1) {
-				continue;
-			}
-			if (k1 != s->k0) {
-				s->k0 = k1;
-				continue;
+/* Undo burrows-wheeler transform on intermediate buffer to produce output.
+   If !len, write up to len bytes of data to buf.  Otherwise write to out_fd.
+   Returns len ? bytes written : RETVAL_OK.  Notice all errors negative #'s. */
+extern int write_bunzip_data(bunzip_data *bd, int out_fd, char *outbuf, int len)
+{
+	unsigned int *dbuf=bd->dbuf;
+	int count,pos,current, run,copies,outbyte,previous,gotcount=0;
+
+	for(;;) {
+		/* If last read was short due to end of file, return last block now */
+		if(bd->writeCount<0) return bd->writeCount;
+		/* If we need to refill dbuf, do it. */
+		if(!bd->writeCount) {
+			int i=read_bunzip_data(bd);
+			if(i) {
+				if(i==RETVAL_LAST_BLOCK) {
+					bd->writeCount=i;
+					return gotcount;
+				} else return i;
 			}
-
-			k1 = bz_get_fast(s);
-			bz_rand_udp_mask(s);
-			k1 ^= ((s->rNToGo == 1) ? 1 : 0);
-			s->nblock_used++;
-			s->state_out_len = ((int)k1) + 4;
-			s->k0 = bz_get_fast(s);
-			bz_rand_udp_mask(s);
-			s->k0 ^= ((s->rNToGo == 1) ? 1 : 0);
-			s->nblock_used++;
 		}
-	} else {
-		/* restore */
-		unsigned int c_calculatedBlockCRC = s->calculatedBlockCRC;
-		unsigned char c_state_out_ch       = s->state_out_ch;
-		int c_state_out_len      = s->state_out_len;
-		int c_nblock_used        = s->nblock_used;
-		int c_k0                 = s->k0;
-		unsigned int	*c_tt                 = s->tt;
-		unsigned int	c_tPos               = s->tPos;
-		char	*cs_next_out          = s->strm->next_out;
-		unsigned int  cs_avail_out         = s->strm->avail_out;
-		/* end restore */
-
-		int        s_save_nblockPP = s->save_nblock+1;
-
-		while (1) {
-			/* try to finish existing run */
-			if (c_state_out_len > 0) {
-				while (TRUE) {
-					if (cs_avail_out == 0) {
-						goto return_notr;
-					}
-					if (c_state_out_len == 1) {
-						break;
-					}
-					*((unsigned char *)(cs_next_out)) = c_state_out_ch;
-					c_calculatedBlockCRC = (c_calculatedBlockCRC << 8) ^
-						BZ2_crc32Table[(c_calculatedBlockCRC >> 24) ^
-						((unsigned char)c_state_out_ch)];
-					c_state_out_len--;
-					cs_next_out++;
-					cs_avail_out--;
-				}
-s_state_out_len_eq_one:
-				{
-					if (cs_avail_out == 0) { 
-						c_state_out_len = 1;
-						goto return_notr;
-					}
-					*((unsigned char *)(cs_next_out)) = c_state_out_ch;
-					c_calculatedBlockCRC = (c_calculatedBlockCRC << 8) ^
-						BZ2_crc32Table[(c_calculatedBlockCRC >> 24) ^
-						((unsigned char)c_state_out_ch)];
-					cs_next_out++;
-					cs_avail_out--;
-				}
-			}   
-			/* can a new run be started? */
-			if (c_nblock_used == s_save_nblockPP) {
-				c_state_out_len = 0; goto return_notr;
-			}
-			c_state_out_ch = c_k0;
-			c_tPos = c_tt[c_tPos];
-			k1 = (unsigned char)(c_tPos & 0xff);
-			c_tPos >>= 8;
-
-			c_nblock_used++;
-
-			if (k1 != c_k0) { 
-				c_k0 = k1;
-				goto s_state_out_len_eq_one; 
-			}
-
-			if (c_nblock_used == s_save_nblockPP) {
-				goto s_state_out_len_eq_one;
-			}
-
-			c_state_out_len = 2;
-			c_tPos = c_tt[c_tPos];
-			k1 = (unsigned char)(c_tPos & 0xff);
-			c_tPos >>= 8;
-
-			c_nblock_used++;
-			if (c_nblock_used == s_save_nblockPP) {
-				continue;
-			}
-			if (k1 != c_k0) {
-				c_k0 = k1;
-				continue;
-			}
-
-			c_state_out_len = 3;
-			c_tPos = c_tt[c_tPos];
-			k1 = (unsigned char)(c_tPos & 0xff);
-			c_tPos >>= 8;
-
-			c_nblock_used++;
-			if (c_nblock_used == s_save_nblockPP) {
-				continue;
+		/* Loop generating output */
+		count=bd->writeCount;
+		pos=bd->writePos;
+		current=bd->writeCurrent;
+		run=bd->writeRun;
+		while(count) {
+			/* If somebody (like busybox tar) wants a certain number of bytes of
+			data from memory instead of written to a file, humor them */
+			if(len && bd->outbufPos>=len) goto dataus_interruptus;
+			count--;
+			/* Follow sequence vector to undo Burrows-Wheeler transform */
+			previous=current;
+			pos=dbuf[pos];
+			current=pos&0xff;
+			pos>>=8;
+			/* Whenever we see 3 consecutive copies of the same byte,
+			   the 4th is a repeat count */
+			if(run++==3) {
+				copies=current;
+				outbyte=previous;
+				current=-1;
+			} else {
+				copies=1;
+				outbyte=current;
 			}
-			if (k1 != c_k0) {
-				c_k0 = k1;
-				continue;
+			/* Output bytes to buffer, flushing to file if necessary */
+			while(copies--) {
+				if(bd->outbufPos == IOBUF_SIZE) flush_bunzip_outbuf(bd,out_fd);
+				bd->outbuf[bd->outbufPos++] = outbyte;
+				bd->dataCRC = (bd->dataCRC << 8)
+								^ bd->crc32Table[(bd->dataCRC >> 24) ^ outbyte];
 			}
-   
-			c_tPos = c_tt[c_tPos];
-			k1 = (unsigned char)(c_tPos & 0xff);
-			c_tPos >>= 8;
-
-			c_nblock_used++;
-			c_state_out_len = ((int)k1) + 4;
-
-			c_tPos = c_tt[c_tPos];
-			c_k0 = (unsigned char)(c_tPos & 0xff);
-			c_tPos >>= 8;
-
-			c_nblock_used++;
+			if(current!=previous) run=0;
 		}
-
-return_notr:
-
-		/* save */
-		s->calculatedBlockCRC = c_calculatedBlockCRC;
-		s->state_out_ch       = c_state_out_ch;
-		s->state_out_len      = c_state_out_len;
-		s->nblock_used        = c_nblock_used;
-		s->k0                 = c_k0;
-		s->tt                 = c_tt;
-		s->tPos               = c_tPos;
-		s->strm->next_out     = cs_next_out;
-		s->strm->avail_out    = cs_avail_out;
-		/* end save */
-	}
-}
-static inline
-int BZ2_bzDecompress(bz_stream *strm)
-{
-	DState* s;
-	s = strm->state;
-
-	while (1) {
-		if (s->state == BZ_X_IDLE) {
-			return BZ_SEQUENCE_ERROR;
+		/* Decompression of this block completed successfully */
+		bd->dataCRC=~(bd->dataCRC);
+		bd->totalCRC=((bd->totalCRC << 1) | (bd->totalCRC >> 31)) ^ bd->dataCRC;
+		/* If this block had a CRC error, force file level CRC error. */
+		if(bd->dataCRC!=bd->headerCRC) {
+			bd->totalCRC=bd->headerCRC+1;
+			return RETVAL_LAST_BLOCK;
 		}
-		if (s->state == BZ_X_OUTPUT) {
-			unRLE_obuf_to_output_FAST(s);
-			if (s->nblock_used == s->save_nblock+1 && s->state_out_len == 0) {
-				s->calculatedBlockCRC = ~(s->calculatedBlockCRC);
-				if (s->calculatedBlockCRC != s->storedBlockCRC) {
-					return BZ_DATA_ERROR;
-				}
-				s->calculatedCombinedCRC = (s->calculatedCombinedCRC << 1) | (s->calculatedCombinedCRC >> 31);
-				s->calculatedCombinedCRC ^= s->calculatedBlockCRC;
-				s->state = BZ_X_BLKHDR_1;
-			} else {
-				return BZ_OK;
-			}
-		}
-		if (s->state >= BZ_X_MAGIC_1) {
-			int r = BZ2_decompress(s);
-			if (r == BZ_STREAM_END) {
-				if (s->calculatedCombinedCRC != s->storedCombinedCRC) {
-					return BZ_DATA_ERROR;
-				}
-				return r;
-			}
-			if (s->state != BZ_X_OUTPUT) {
-				return r;
+dataus_interruptus:
+		bd->writeCount=count;
+		if(len) {
+			gotcount+=bd->outbufPos;
+			memcpy(outbuf,bd->outbuf,len);
+			/* If we got enough data, checkpoint loop state and return */
+			if((len-=bd->outbufPos)<1) {
+				bd->outbufPos-=len;
+				if(bd->outbufPos)
+					memmove(bd->outbuf,bd->outbuf+len,bd->outbufPos);
+				bd->writePos=pos;
+				bd->writeCurrent=current;
+				bd->writeRun=run;
+				return gotcount;
 			}
 		}
 	}
-
-	return(0);  /*NOTREACHED*/
 }
 
-extern ssize_t read_bz2(int fd, void *buf, size_t count)
+/* Allocate the structure, read file header.  If !len, src_fd contains
+   filehandle to read from.  Else inbuf contains data. */
+extern int start_bunzip(bunzip_data **bdp, int src_fd, char *inbuf, int len)
 {
-	int n, ret;
-
-	bzerr = BZ_OK;
-	if (count == 0) {
-		return(0);
+	bunzip_data *bd;
+	unsigned int i,j,c;
+
+	/* Figure out how much data to allocate */
+	i=sizeof(bunzip_data);
+	if(!len) i+=IOBUF_SIZE;
+	/* Allocate bunzip_data.  Most fields initialize to zero. */
+	if(!(bd=*bdp=malloc(i))) return RETVAL_OUT_OF_MEMORY;
+	memset(bd,0,sizeof(bunzip_data));
+	if(len) {
+		bd->inbuf=inbuf;
+		bd->inbufCount=len;
+		bd->in_fd=-1;
+	} else {
+		bd->inbuf=(char *)(bd+1);
+		bd->in_fd=src_fd;
 	}
-	bzf->strm.avail_out = count;
-	bzf->strm.next_out = buf;
-
-	while (1) {
-		if (bzf->strm.avail_in == 0) {
-			n = bb_xread(bzf->fd, bzf->buf, BZ_MAX_UNUSED);
-			if (n == 0) {
-				break;
-			}
-			bzf->bufN = n;
-			bzf->strm.avail_in = bzf->bufN;
-			bzf->strm.next_in = bzf->buf;
-		}
-
-		ret = BZ2_bzDecompress(&(bzf->strm));
-
-		if ((ret != BZ_OK) && (ret != BZ_STREAM_END)) {
-			bb_error_msg_and_die("Error decompressing");
-		}
-
-		if (ret == BZ_STREAM_END) {
-			bzerr = BZ_STREAM_END;
-			return(count - bzf->strm.avail_out);
-		}
-		if (bzf->strm.avail_out == 0) {
-			bzerr = BZ_OK;
-			return(count);
-		}
+	/* Init the CRC32 table (big endian) */
+	for(i=0;i<256;i++) {
+		c=i<<24;
+		for(j=8;j;j--)
+			c=c&0x80000000 ? (c<<1)^0x04c11db7 : (c<<1);
+		bd->crc32Table[i]=c;
 	}
-	return(0);
+	/* Setup for I/O error handling via longjmp */
+	i=setjmp(bd->jmpbuf);
+	if(i) return i;
+	/* Ensure that file starts with "BZh" */
+    for(i=0;i<3;i++) if(get_bits(bd,8)!="BZh"[i]) return RETVAL_NOT_BZIP_DATA;
+	/* Next byte ascii '1'-'9', indicates block size in units of 100k of
+	   uncompressed data.  Allocate intermediate buffer for block. */
+	i=get_bits(bd,8);
+	if (i<'1' || i>'9') return RETVAL_NOT_BZIP_DATA;
+	bd->dbufSize=100000*(i-'0');
+	if(!(bd->dbuf=malloc(bd->dbufSize * sizeof(int))))
+		return RETVAL_OUT_OF_MEMORY;
+	return RETVAL_OK;
 }
 
-extern void BZ2_bzReadOpen(int fd, void *unused, int nUnused)
+extern char *uncompressStream(int src_fd, int dst_fd)
 {
-	DState *s;
-
-	bzf = xmalloc(sizeof(bzFile));
-	bzf->initialisedOk = FALSE;
-	bzf->fd        = fd;
-	bzf->bufN      = 0;
-
-	s = xmalloc(sizeof(DState));
-	s->strm = &bzf->strm;
-	s->state = BZ_X_MAGIC_1;
-	s->bsLive = 0;
-	s->bsBuff = 0;
-	s->calculatedCombinedCRC = 0;
-	s->tt = NULL;
-	s->currBlockNo = 0;
-	bzf->strm.state = s;
+	bunzip_data *bd;
+	int i;
 
-	while (nUnused > 0) {
-		bzf->buf[bzf->bufN] = *((unsigned char *)(unused));
-		bzf->bufN++;
-		unused = ((void *)( 1 + ((unsigned char *)(unused))  ));
-		nUnused--;
+	if(!(i=start_bunzip(&bd,src_fd,0,0))) {
+		i=write_bunzip_data(bd,dst_fd,0,0);
+		if(i==RETVAL_LAST_BLOCK && bd->headerCRC==bd->totalCRC) i=RETVAL_OK;
 	}
-	bzf->strm.avail_in = bzf->bufN;
-	bzf->strm.next_in  = bzf->buf;
+	flush_bunzip_outbuf(bd,dst_fd);
+	if(bd->dbuf) free(bd->dbuf);
+	free(bd);
+	return bunzip_errors[-i];
+}
 
-	bzf->initialisedOk = TRUE;
+/* This new version is not yet properly integrated with tar */
+extern ssize_t read_bz2(int fd, void *buf, size_t count)
+{
+#warning FIXME
+	return(0);
+}
 
+extern void BZ2_bzReadOpen(int fd, void *unused, int nUnused)
+{
+#warning FIXME
 	return;
 }
-
-extern unsigned char uncompressStream(int src_fd, int dst_fd)
+extern void BZ2_bzReadClose(void)
 {
-	unsigned char unused[BZ_MAX_UNUSED];
-	unsigned char *unusedTmp;
-	unsigned char obuf[5000];
-	int nread;
-	int nUnused;
-	int streamNo;
-	int i;
-
-	nUnused = 0;
-	streamNo = 0;
-
-	while(1) {
-		BZ2_bzReadOpen(src_fd, unused, nUnused);
-		streamNo++;
-
-		while (bzerr == BZ_OK) {
-			nread = read_bz2(src_fd, obuf, 5000);
-			if (bzerr == BZ_DATA_ERROR_MAGIC) {
-				bb_error_msg_and_die("invalid magic");
-			}
-			if (((bzerr == BZ_OK) || (bzerr == BZ_STREAM_END)) && (nread > 0)) {
-				if (write(dst_fd, obuf, nread) != nread) {
-					BZ2_bzReadClose();
-					bb_perror_msg_and_die("Couldnt write to file");
-				}
-			}
-		}
-		nUnused = bzf->strm.avail_in;
-		unusedTmp = bzf->strm.next_in;
-
-		for (i = 0; i < nUnused; i++) {
-			unused[i] = unusedTmp[i];
-		}
-		BZ2_bzReadClose();
-		if (nUnused == 0) {
-			break;
-		}
-	}
-
-	close(src_fd);
-	if (dst_fd != fileno(stdout)) {
-		close(dst_fd);
-	}
-	return TRUE;
+#warning FIXME
 }
 
+#if 0
+/* Dumb little test thing, decompress stdin to stdout */
+int main(int argc, char *argv[])
+{
+	char *c=uncompressStream(0,1);
+	fprintf(stderr,"\n%s\n", c ? c : "Completed OK");
+}
+#endif