Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdevelop@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 796 insertions, 0 deletions

diff --git a/parts/documentation/protocols/chm/decompress.cpp b/parts/documentation/protocols/chm/decompress.cpp
new file mode 100644
index 00000000..0356d86e
--- /dev/null
+++ b/parts/documentation/protocols/chm/decompress.cpp
@@ -0,0 +1,796 @@
+/*  Most of this file is taken from:
+    cabextract 0.5 - a program to extract Microsoft Cabinet files
+    (C) 2000-2001 Stuart Caie <kyzer@4u.net>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public License
+    along with this library; see the file COPYING.LIB.  If not, write to
+    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+    Boston, MA 02111-1307, USA.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "decompress.h"
+
+int make_decode_table(ULONG nsyms, ULONG nbits, UBYTE *length, UWORD *table);
+int lzx_read_lens(UBYTE *lens, ULONG first, ULONG last, lzx_bits *lb);
+
+
+/*--------------------------------------------------------------------------*/
+/* our archiver information / state */
+
+/* LZX stuff */
+
+/* some constants defined by the LZX specification */
+#define LZX_MIN_MATCH                (2)
+#define LZX_MAX_MATCH                (257)
+#define LZX_NUM_CHARS                (256)
+#define LZX_BLOCKTYPE_INVALID        (0)   /* also blocktypes 4-7 invalid */
+#define LZX_BLOCKTYPE_VERBATIM       (1)
+#define LZX_BLOCKTYPE_ALIGNED        (2)
+#define LZX_BLOCKTYPE_UNCOMPRESSED   (3)
+#define LZX_PRETREE_NUM_ELEMENTS     (20)
+#define LZX_ALIGNED_NUM_ELEMENTS     (8)   /* aligned offset tree #elements */
+#define LZX_NUM_PRIMARY_LENGTHS      (7)   /* this one missing from spec! */
+#define LZX_NUM_SECONDARY_LENGTHS    (249) /* length tree #elements */
+
+/* LZX huffman defines: tweak tablebits as desired */
+#define LZX_PRETREE_MAXSYMBOLS  (LZX_PRETREE_NUM_ELEMENTS)
+#define LZX_PRETREE_TABLEBITS   (6)
+#define LZX_MAINTREE_MAXSYMBOLS (LZX_NUM_CHARS + 50*8)
+#define LZX_MAINTREE_TABLEBITS  (12)
+#define LZX_LENGTH_MAXSYMBOLS   (LZX_NUM_SECONDARY_LENGTHS+1)
+#define LZX_LENGTH_TABLEBITS    (12)
+#define LZX_ALIGNED_MAXSYMBOLS  (LZX_ALIGNED_NUM_ELEMENTS)
+#define LZX_ALIGNED_TABLEBITS   (7)
+
+#define LZX_LENTABLE_SAFETY (64) /* we allow length table decoding overruns */
+
+#define LZX_DECLARE_TABLE(tbl) \
+  UWORD tbl##_table[(1<<LZX_##tbl##_TABLEBITS) + (LZX_##tbl##_MAXSYMBOLS<<1)];\
+  UBYTE tbl##_len  [LZX_##tbl##_MAXSYMBOLS + LZX_LENTABLE_SAFETY]
+
+struct LZXstate
+{
+	UBYTE *window;		   /* the actual decoding window              */
+	ULONG window_size;	   /* window size (32Kb through 2Mb)          */
+	ULONG actual_size;	   /* window size when it was first allocated */
+	ULONG window_posn;	   /* current offset within the window        */
+	ULONG R0, R1, R2;	   /* for the LRU offset system               */
+	UWORD main_elements;   /* number of main tree elements            */
+	int   header_read;	   /* have we started decoding at all yet?    */
+	UWORD block_type;	   /* type of this block                      */
+	ULONG block_length;	   /* uncompressed length of this block       */
+	ULONG block_remaining; /* uncompressed bytes still left to decode */
+	ULONG frames_read;	   /* the number of CFDATA blocks processed   */
+	LONG  intel_filesize;  /* magic header value used for transform   */
+	LONG  intel_curpos;	   /* current offset in transform space       */
+	int   intel_started;   /* have we seen any translatable data yet? */
+
+	LZX_DECLARE_TABLE(PRETREE);
+	LZX_DECLARE_TABLE(MAINTREE);
+	LZX_DECLARE_TABLE(LENGTH);
+	LZX_DECLARE_TABLE(ALIGNED);
+};
+
+
+/* generic stuff */
+#define CAB(x) (decomp_state.x)
+#define LZX(x) (decomp_state.lzx.x)
+#define DECR_OK           (0)
+#define DECR_DATAFORMAT   (1)
+#define DECR_ILLEGALDATA  (2)
+#define DECR_NOMEMORY     (3)
+#define DECR_CHECKSUM     (4)
+#define DECR_INPUT        (5)
+#define DECR_OUTPUT       (6)
+
+struct
+{
+    struct LZXstate lzx;
+} decomp_state;
+
+
+/* LZX decruncher */
+
+/* Microsoft's LZX document and their implementation of the
+ * com.ms.util.cab Java package do not concur.
+ *
+ * In the LZX document, there is a table showing the correlation between
+ * window size and the number of position slots. It states that the 1MB
+ * window = 40 slots and the 2MB window = 42 slots. In the implementation,
+ * 1MB = 42 slots, 2MB = 50 slots. The actual calculation is 'find the
+ * first slot whose position base is equal to or more than the required
+ * window size'. This would explain why other tables in the document refer
+ * to 50 slots rather than 42.
+ *
+ * The constant NUM_PRIMARY_LENGTHS used in the decompression pseudocode
+ * is not defined in the specification.
+ *
+ * The LZX document does not state the uncompressed block has an
+ * uncompressed length field. Where does this length field come from, so
+ * we can know how large the block is? The implementation has it as the 24
+ * bits following after the 3 blocktype bits, before the alignment
+ * padding.
+ *
+ * The LZX document states that aligned offset blocks have their aligned
+ * offset huffman tree AFTER the main and length trees. The implementation
+ * suggests that the aligned offset tree is BEFORE the main and length
+ * trees.
+ *
+ * The LZX document decoding algorithm states that, in an aligned offset
+ * block, if an extra_bits value is 1, 2 or 3, then that number of bits
+ * should be read and the result added to the match offset. This is
+ * correct for 1 and 2, but not 3, where just a huffman symbol (using the
+ * aligned tree) should be read.
+ *
+ * Regarding the E8 preprocessing, the LZX document states 'No translation
+ * may be performed on the last 6 bytes of the input block'. This is
+ * correct.  However, the pseudocode provided checks for the *E8 leader*
+ * up to the last 6 bytes. If the leader appears between -10 and -7 bytes
+ * from the end, this would cause the next four bytes to be modified, at
+ * least one of which would be in the last 6 bytes, which is not allowed
+ * according to the spec.
+ *
+ * The specification states that the huffman trees must always contain at
+ * least one element. However, many CAB files contain blocks where the
+ * length tree is completely empty (because there are no matches), and
+ * this is expected to succeed.
+ */
+
+
+/* LZX uses what it calls 'position slots' to represent match offsets.
+ * What this means is that a small 'position slot' number and a small
+ * offset from that slot are encoded instead of one large offset for
+ * every match.
+ * - position_base is an index to the position slot bases
+ * - extra_bits states how many bits of offset-from-base data is needed.
+ */
+static ULONG position_base[51];
+static UBYTE extra_bits[51];
+
+
+int LZXinit(int window) {
+	ULONG wndsize = 1 << window;
+	int i, j, posn_slots;
+
+	/* LZX supports window sizes of 2^15 (32Kb) through 2^21 (2Mb) */
+	/* if a previously allocated window is big enough, keep it     */
+	if (window < 15 || window > 21)	return DECR_DATAFORMAT;
+	if (LZX(actual_size) < wndsize)
+	{
+		if (LZX(window)) free(LZX(window));
+		LZX(window) = NULL;
+	}
+	if (!LZX(window))
+	{
+		if (!(LZX(window) = (UBYTE*)malloc(wndsize))) return DECR_NOMEMORY;
+		LZX(actual_size) = wndsize;
+	}
+	LZX(window_size) = wndsize;
+
+	/* initialise static tables */
+	for (i=0, j=0; i <= 49; i += 2)
+	{
+		extra_bits[i] = extra_bits[i+1] = j; /* 0,0,0,0,1,1,2,2,3,3... */
+		if ((i != 0) && (j < 17)) j++; /* 0,0,1,2,3,4...15,16,17,17,17,17... */
+	}
+	for (i=0, j=0; i <= 50; i++)
+	{
+		position_base[i] = j; /* 0,1,2,3,4,6,8,12,16,24,32,... */
+		j += 1 << extra_bits[i]; /* 1,1,1,1,2,2,4,4,8,8,16,16,32,32,... */
+	}
+
+	/* calculate required position slots */
+	if (window == 20) posn_slots = 42;
+	else if (window == 21) posn_slots = 50;
+	else posn_slots	= window << 1;
+
+	/*posn_slots=i=0; while (i < wndsize) i += 1 << extra_bits[posn_slots++]; */
+
+
+	LZX(R0)  =  LZX(R1)  = LZX(R2) = 1;
+	LZX(main_elements)   = LZX_NUM_CHARS + (posn_slots << 3);
+	LZX(header_read)     = 0;
+	LZX(frames_read)     = 0;
+	LZX(block_remaining) = 0;
+	LZX(block_type)      = LZX_BLOCKTYPE_INVALID;
+	LZX(intel_curpos)    = 0;
+	LZX(intel_started)   = 0;
+	LZX(window_posn)     = 0;
+
+	/* initialise tables to 0 (because deltas will be applied to them) */
+	for (i = 0; i < LZX_MAINTREE_MAXSYMBOLS; i++) LZX(MAINTREE_len)[i] = 0;
+	for (i = 0; i < LZX_LENGTH_MAXSYMBOLS; i++)	  LZX(LENGTH_len)[i]   = 0;
+
+	return DECR_OK;
+}
+
+
+/* Bitstream reading macros:
+ *
+ * INIT_BITSTREAM    should be used first to set up the system
+ * READ_BITS(var,n)  takes N bits from the buffer and puts them in var
+ *
+ * ENSURE_BITS(n)    ensures there are at least N bits in the bit buffer
+ * PEEK_BITS(n)      extracts (without removing) N bits from the bit buffer
+ * REMOVE_BITS(n)    removes N bits from the bit buffer
+ *
+ * These bit access routines work by using the area beyond the MSB and the
+ * LSB as a free source of zeroes. This avoids having to mask any bits.
+ * So we have to know the bit width of the bitbuffer variable. This is
+ * sizeof(ULONG) * 8, also defined as ULONG_BITS
+ */
+
+/* number of bits in ULONG. Note: This must be at multiple of 16, and at
+ * least 32 for the bitbuffer code to work (ie, it must be able to ensure
+ * up to 17 bits - that's adding 16 bits when there's one bit left, or
+ * adding 32 bits when there are no bits left. The code should work fine
+ * for machines where ULONG >= 32 bits.
+ */
+#define ULONG_BITS (sizeof(ULONG)<<3)
+
+#define INIT_BITSTREAM do { bitsleft = 0; bitbuf = 0; } while (0)
+
+#define ENSURE_BITS(n)							\
+  while (bitsleft < (n)) {						\
+    bitbuf |= ((inpos[1]<<8)|inpos[0]) << (ULONG_BITS-16 - bitsleft);	\
+    bitsleft += 16; inpos+=2;						\
+  }
+
+#define PEEK_BITS(n)   (bitbuf >> (ULONG_BITS - (n)))
+#define REMOVE_BITS(n) ((bitbuf <<= (n)), (bitsleft -= (n)))
+
+#define READ_BITS(v,n) do {						\
+  ENSURE_BITS(n);							\
+  (v) = PEEK_BITS(n);							\
+  REMOVE_BITS(n);							\
+} while (0)
+
+
+/* Huffman macros */
+
+#define TABLEBITS(tbl)   (LZX_##tbl##_TABLEBITS)
+#define MAXSYMBOLS(tbl)  (LZX_##tbl##_MAXSYMBOLS)
+#define SYMTABLE(tbl)    (LZX(tbl##_table))
+#define LENTABLE(tbl)    (LZX(tbl##_len))
+
+/* BUILD_TABLE(tablename) builds a huffman lookup table from code lengths.
+ * In reality, it just calls make_decode_table() with the appropriate
+ * values - they're all fixed by some #defines anyway, so there's no point
+ * writing each call out in full by hand.
+ */
+#define BUILD_TABLE(tbl)						\
+  if (make_decode_table(						\
+    MAXSYMBOLS(tbl), TABLEBITS(tbl), LENTABLE(tbl), SYMTABLE(tbl)	\
+  )) { return DECR_ILLEGALDATA; }
+
+
+/* READ_HUFFSYM(tablename, var) decodes one huffman symbol from the
+ * bitstream using the stated table and puts it in var.
+ */
+#define READ_HUFFSYM(tbl,var) do {					\
+  ENSURE_BITS(16);							\
+  hufftbl = SYMTABLE(tbl);						\
+  if ((i = hufftbl[PEEK_BITS(TABLEBITS(tbl))]) >= MAXSYMBOLS(tbl)) {	\
+    j = 1 << (ULONG_BITS - TABLEBITS(tbl));				\
+    do {								\
+      j >>= 1; i <<= 1; i |= (bitbuf & j) ? 1 : 0;			\
+      if (!j) { return DECR_ILLEGALDATA; }	                        \
+    } while ((i = hufftbl[i]) >= MAXSYMBOLS(tbl));			\
+  }									\
+  j = LENTABLE(tbl)[(var) = i];						\
+  REMOVE_BITS(j);							\
+} while (0)
+
+
+/* READ_LENGTHS(tablename, first, last) reads in code lengths for symbols
+ * first to last in the given table. The code lengths are stored in their
+ * own special LZX way.
+ */
+#define READ_LENGTHS(tbl,first,last) do { \
+  lb.bb = bitbuf; lb.bl = bitsleft; lb.ip = inpos; \
+  if (lzx_read_lens(LENTABLE(tbl),(first),(last),&lb)) { \
+    return DECR_ILLEGALDATA; \
+  } \
+  bitbuf = lb.bb; bitsleft = lb.bl; inpos = lb.ip; \
+} while (0)
+
+
+/* make_decode_table(nsyms, nbits, length[], table[])
+ *
+ * This function was coded by David Tritscher. It builds a fast huffman
+ * decoding table out of just a canonical huffman code lengths table.
+ *
+ * nsyms  = total number of symbols in this huffman tree.
+ * nbits  = any symbols with a code length of nbits or less can be decoded
+ *          in one lookup of the table.
+ * length = A table to get code lengths from [0 to syms-1]
+ * table  = The table to fill up with decoded symbols and pointers.
+ *
+ * Returns 0 for OK or 1 for error
+ */
+
+int make_decode_table(ULONG nsyms, ULONG nbits, UBYTE *length, UWORD *table) {
+	register UWORD sym;
+	register ULONG leaf;
+	register UBYTE bit_num = 1;
+	ULONG fill;
+	ULONG pos         = 0; /* the current position in the decode table */
+	ULONG table_mask  = 1 << nbits;
+	ULONG bit_mask    = table_mask >> 1; /* don't do 0 length codes */
+	ULONG next_symbol = bit_mask; /* base of allocation for long codes */
+
+	/* fill entries for codes short enough for a direct mapping */
+	while (bit_num <= nbits)
+	{
+		for (sym = 0; sym < nsyms; sym++)
+		{
+			if (length[sym] == bit_num)
+			{
+				leaf = pos;
+
+				if ((pos += bit_mask) > table_mask)	return 1; /* table overrun */
+
+				/* fill all possible lookups of this symbol with the symbol itself */
+				fill = bit_mask;
+				while (fill-- > 0) table[leaf++] = sym;
+			}
+		}
+		bit_mask >>= 1;
+		bit_num++;
+	}
+
+	/* if there are any codes longer than nbits */
+	if (pos != table_mask)
+	{
+		/* clear the remainder of the table */
+		for (sym = pos; sym < table_mask; sym++) table[sym] = 0;
+
+		/* give ourselves room for codes to grow by up to 16 more bits */
+		pos <<= 16;
+		table_mask <<= 16;
+		bit_mask = 1 << 15;
+
+		while (bit_num <= 16)
+		{
+			for (sym = 0; sym < nsyms; sym++)
+			{
+				if (length[sym] == bit_num)
+				{
+					leaf = pos >> 16;
+					for (fill = 0; fill < bit_num - nbits; fill++)
+					{
+						/* if this path hasn't been taken yet, 'allocate' two entries */
+						if (table[leaf] == 0)
+						{
+							table[(next_symbol << 1)] = 0;
+							table[(next_symbol << 1) + 1] = 0;
+							table[leaf] = next_symbol++;
+						}
+						/* follow the path and select either left or right for next bit */
+						leaf = table[leaf] << 1;
+						if ((pos >> (15-fill)) & 1)	leaf++;
+					}
+					table[leaf] = sym;
+
+					if ((pos += bit_mask) > table_mask)	return 1; /* table overflow */
+				}
+			}
+			bit_mask >>= 1;
+			bit_num++;
+		}
+	}
+
+	/* full table? */
+	if (pos == table_mask) return 0;
+
+	/* either erroneous table, or all elements are 0 - let's find out. */
+	for (sym = 0; sym < nsyms; sym++) if (length[sym]) return 1;
+	return 0;
+}
+
+int lzx_read_lens(UBYTE *lens, ULONG first, ULONG last, lzx_bits *lb) {
+	ULONG i,j, x,y;
+	int z;
+
+	register ULONG bitbuf = lb->bb;
+	register int bitsleft = lb->bl;
+	UBYTE *inpos = lb->ip;
+	UWORD *hufftbl;
+
+	for (x = 0; x < 20; x++)
+	{
+		READ_BITS(y, 4);
+		LENTABLE(PRETREE)[x] = y;
+	}
+	BUILD_TABLE(PRETREE);
+
+	for (x = first; x < last;)
+	{
+		READ_HUFFSYM(PRETREE, z);
+		if (z == 17)
+		{
+			READ_BITS(y, 4); y += 4;
+			while (y--)	lens[x++] = 0;
+		}
+		else if (z == 18)
+		{
+			READ_BITS(y, 5); y += 20;
+			while (y--)	lens[x++] = 0;
+		}
+		else if (z == 19)
+		{
+			READ_BITS(y, 1); y += 4;
+			READ_HUFFSYM(PRETREE, z);
+			z = lens[x] - z; if (z < 0)	z += 17;
+			while (y--)	lens[x++] = z;
+		}
+		else
+		{
+			z = lens[x] - z; if (z < 0)	z += 17;
+			lens[x++] = z;
+		}
+	}
+
+	lb->bb = bitbuf;
+	lb->bl = bitsleft;
+	lb->ip = inpos;
+	return 0;
+}
+
+int LZXdecompress(UBYTE* inpos, int inlen, UBYTE* outpos, int outlen) {
+	UBYTE *endinp = inpos + inlen;
+	UBYTE *window = LZX(window);
+	UBYTE *runsrc, *rundest;
+	UWORD *hufftbl;	/* used in READ_HUFFSYM macro as chosen decoding table */
+
+	ULONG window_posn = LZX(window_posn);
+	ULONG window_size = LZX(window_size);
+	ULONG R0 = LZX(R0);
+	ULONG R1 = LZX(R1);
+	ULONG R2 = LZX(R2);
+
+	register ULONG bitbuf;
+	register int bitsleft;
+	ULONG match_offset, i,j,k; /* ijk used in READ_HUFFSYM macro */
+	lzx_bits lb;	/* used in READ_LENGTHS macro */
+
+	int togo = outlen, this_run, main_element, aligned_bits;
+	int match_length, length_footer, extra, verbatim_bits;
+
+	INIT_BITSTREAM;
+
+	/* read header if necessary */
+	if (!LZX(header_read))
+	{
+		i = j = 0;
+		READ_BITS(k, 1); if (k)
+		{
+			READ_BITS(i,16); READ_BITS(j,16);
+		}
+		LZX(intel_filesize) = (i << 16) | j; /* or 0 if not encoded */
+		LZX(header_read) = 1;
+	}
+
+	/* main decoding loop */
+	while (togo > 0)
+	{
+		/* last block finished, new block expected */
+		if (LZX(block_remaining) == 0)
+		{
+			if (LZX(block_type) == LZX_BLOCKTYPE_UNCOMPRESSED)
+			{
+				if (LZX(block_length) & 1) inpos++;	/* realign bitstream to word */
+				INIT_BITSTREAM;
+			}
+
+			READ_BITS(LZX(block_type), 3);
+			READ_BITS(i, 16);
+			READ_BITS(j, 8);
+			LZX(block_remaining) = LZX(block_length) = (i << 8) | j;
+
+			switch (LZX(block_type))
+			{
+				case LZX_BLOCKTYPE_ALIGNED:
+					for (i = 0; i < 8; i++)
+					{
+						READ_BITS(j, 3); LENTABLE(ALIGNED)[i] = j;
+					}
+					BUILD_TABLE(ALIGNED);
+					/* rest of aligned header is same as verbatim */
+
+				case LZX_BLOCKTYPE_VERBATIM:
+					READ_LENGTHS(MAINTREE, 0, 256);
+					READ_LENGTHS(MAINTREE, 256, LZX(main_elements));
+					BUILD_TABLE(MAINTREE);
+					if (LENTABLE(MAINTREE)[0xE8] != 0) LZX(intel_started) = 1;
+
+					READ_LENGTHS(LENGTH, 0, LZX_NUM_SECONDARY_LENGTHS);
+					BUILD_TABLE(LENGTH);
+					break;
+
+				case LZX_BLOCKTYPE_UNCOMPRESSED:
+					LZX(intel_started) = 1;	/* because we can't assume otherwise */
+					ENSURE_BITS(16); /* get up to 16 pad bits into the buffer */
+					if (bitsleft > 16) inpos -= 2; /* and align the bitstream! */
+					R0 = inpos[0]|(inpos[1]<<8)|(inpos[2]<<16)|(inpos[3]<<24);inpos+=4;
+					R1 = inpos[0]|(inpos[1]<<8)|(inpos[2]<<16)|(inpos[3]<<24);inpos+=4;
+					R2 = inpos[0]|(inpos[1]<<8)|(inpos[2]<<16)|(inpos[3]<<24);inpos+=4;
+					break;
+
+				default:
+					return DECR_ILLEGALDATA;
+			}
+		}
+
+		/* buffer exhaustion check */
+		if (inpos > endinp)
+		{
+			/* it's possible to have a file where the next run is less than
+			 * 16 bits in size. In this case, the READ_HUFFSYM() macro used
+			 * in building the tables will exhaust the buffer, so we should
+			 * allow for this, but not allow those accidentally read bits to
+			 * be used (so we check that there are at least 16 bits
+			 * remaining - in this boundary case they aren't really part of
+			 * the compressed data)
+			 */
+			if (inpos > (endinp+2) || bitsleft < 16) return DECR_ILLEGALDATA;
+		}
+
+		while ((this_run = LZX(block_remaining)) > 0 && togo > 0)
+		{
+			if (this_run > togo) this_run = togo;
+			togo -= this_run;
+			LZX(block_remaining) -= this_run;
+
+			/* apply 2^x-1 mask */
+			window_posn &= window_size - 1;
+			/* runs can't straddle the window wraparound */
+			if ((window_posn + this_run) > window_size)
+				return DECR_DATAFORMAT;
+
+			switch (LZX(block_type))
+			{
+				
+				case LZX_BLOCKTYPE_VERBATIM:
+					while (this_run > 0)
+					{
+						READ_HUFFSYM(MAINTREE, main_element);
+
+						if (main_element < LZX_NUM_CHARS)
+						{
+							/* literal: 0 to LZX_NUM_CHARS-1 */
+							window[window_posn++] = main_element;
+							this_run--;
+						}
+						else
+						{
+							/* match: LZX_NUM_CHARS + ((slot<<3) | length_header (3 bits)) */
+							main_element -= LZX_NUM_CHARS;
+
+							match_length = main_element & LZX_NUM_PRIMARY_LENGTHS;
+							if (match_length == LZX_NUM_PRIMARY_LENGTHS)
+							{
+								READ_HUFFSYM(LENGTH, length_footer);
+								match_length += length_footer;
+							}
+							match_length += LZX_MIN_MATCH;
+
+							match_offset = main_element >> 3;
+
+							if (match_offset > 2)
+							{
+								/* not repeated offset */
+								if (match_offset != 3)
+								{
+									extra = extra_bits[match_offset];
+									READ_BITS(verbatim_bits, extra);
+									match_offset = position_base[match_offset] - 2 + verbatim_bits;
+								}
+								else
+								{
+									match_offset = 1;
+								}
+
+								/* update repeated offset LRU queue */
+								R2 = R1; R1 = R0; R0 = match_offset;
+							}
+							else if (match_offset == 0)
+							{
+								match_offset = R0;
+							}
+							else if (match_offset == 1)
+							{
+								match_offset = R1;
+								R1 = R0; R0 = match_offset;
+							}
+							else /* match_offset == 2 */
+							{
+								match_offset = R2;
+								R2 = R0; R0 = match_offset;
+							}
+
+							rundest = window + window_posn;
+							runsrc  = rundest - match_offset;
+							window_posn += match_length;
+							this_run -= match_length;
+
+							/* copy any wrapped around source data */
+							while ((runsrc < window) && (match_length-- > 0))
+							{
+								*rundest++ = *(runsrc + window_size); runsrc++;
+							}
+							/* copy match data - no worries about destination wraps */
+							while (match_length-- > 0) *rundest++ = *runsrc++;
+
+						}
+					}
+					break;
+
+				case LZX_BLOCKTYPE_ALIGNED:
+					while (this_run > 0)
+					{
+						READ_HUFFSYM(MAINTREE, main_element);
+
+						if (main_element < LZX_NUM_CHARS)
+						{
+							/* literal: 0 to LZX_NUM_CHARS-1 */
+							window[window_posn++] = main_element;
+							this_run--;
+						}
+						else
+						{
+							/* match: LZX_NUM_CHARS + ((slot<<3) | length_header (3 bits)) */
+							main_element -= LZX_NUM_CHARS;
+
+							match_length = main_element & LZX_NUM_PRIMARY_LENGTHS;
+							if (match_length == LZX_NUM_PRIMARY_LENGTHS)
+							{
+								READ_HUFFSYM(LENGTH, length_footer);
+								match_length += length_footer;
+							}
+							match_length += LZX_MIN_MATCH;
+
+							match_offset = main_element >> 3;
+
+							if (match_offset > 2)
+							{
+								/* not repeated offset */
+								extra = extra_bits[match_offset];
+								match_offset = position_base[match_offset] - 2;
+								if (extra > 3)
+								{
+									/* verbatim and aligned bits */
+									extra -= 3;
+									READ_BITS(verbatim_bits, extra);
+									match_offset += (verbatim_bits << 3);
+									READ_HUFFSYM(ALIGNED, aligned_bits);
+									match_offset += aligned_bits;
+								}
+								else if (extra == 3)
+								{
+									/* aligned bits only */
+									READ_HUFFSYM(ALIGNED, aligned_bits);
+									match_offset += aligned_bits;
+								}
+								else if (extra > 0)
+								{ /* extra==1, extra==2 */
+									/* verbatim bits only */
+									READ_BITS(verbatim_bits, extra);
+									match_offset += verbatim_bits;
+								}
+								else /* extra == 0 */
+								{
+									/* ??? */
+									match_offset = 1;
+								}
+
+								/* update repeated offset LRU queue */
+								R2 = R1; R1 = R0; R0 = match_offset;
+							}
+							else if (match_offset == 0)
+							{
+								match_offset = R0;
+							}
+							else if (match_offset == 1)
+							{
+								match_offset = R1;
+								R1 = R0; R0 = match_offset;
+							}
+							else /* match_offset == 2 */
+							{
+								match_offset = R2;
+								R2 = R0; R0 = match_offset;
+							}
+
+							rundest = window + window_posn;
+							runsrc  = rundest - match_offset;
+							window_posn += match_length;
+							this_run -= match_length;
+
+							/* copy any wrapped around source data */
+							while ((runsrc < window) && (match_length-- > 0))
+							{
+								*rundest++ = *(runsrc + window_size); runsrc++;
+							}
+							/* copy match data - no worries about destination wraps */
+							while (match_length-- > 0) *rundest++ = *runsrc++;
+
+						}
+					}
+					break;
+
+				case LZX_BLOCKTYPE_UNCOMPRESSED:
+					if ((inpos + this_run) > endinp) return DECR_ILLEGALDATA;
+					memcpy(window + window_posn, inpos, (size_t) this_run);
+					inpos += this_run; window_posn += this_run;
+					break;
+
+				default:
+					return DECR_ILLEGALDATA; /* might as well */
+			}
+
+		}
+	}
+
+	if (togo != 0) return DECR_ILLEGALDATA;
+	memcpy(outpos, window + ((!window_posn) ? window_size : window_posn) -
+		   outlen, (size_t) outlen);
+
+	LZX(window_posn) = window_posn;
+	LZX(R0) = R0;
+	LZX(R1) = R1;
+	LZX(R2) = R2;
+
+	/* intel E8 decoding */
+	if ((LZX(frames_read)++ < 32768) && LZX(intel_filesize) != 0)
+	{
+		if (outlen <= 6 || !LZX(intel_started))
+		{
+			LZX(intel_curpos) += outlen;
+		}
+		else
+		{
+			UBYTE *data    = outpos;
+			UBYTE *dataend = data + outlen - 10;
+			LONG curpos    = LZX(intel_curpos);
+			LONG filesize  = LZX(intel_filesize);
+			LONG abs_off, rel_off;
+
+			LZX(intel_curpos) = curpos + outlen;
+
+			while (data < dataend)
+			{
+				if (*data++ != 0xE8)
+				{
+					curpos++; continue;
+				}
+				abs_off = data[0] | (data[1]<<8) | (data[2]<<16) | (data[3]<<24);
+				if ((abs_off >= -curpos) && (abs_off < filesize))
+				{
+					rel_off = (abs_off >= 0) ? abs_off - curpos : abs_off + filesize;
+					data[0] = (UBYTE) rel_off;
+					data[1] = (UBYTE) (rel_off >> 8);
+					data[2] = (UBYTE) (rel_off >> 16);
+					data[3] = (UBYTE) (rel_off >> 24);
+				}
+				data += 4;
+				curpos += 5;
+			}
+		}
+	}
+	return DECR_OK;
+}
+