Adding upstream version 1.15~rc1.upstream/1.15_rc1

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

17 files changed, 362 insertions, 280 deletions

diff --git a/AUTHORS b/AUTHORS
index ada24df..5b4d233 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -4,4 +4,4 @@ The ideas embodied in lzip are due to (at least) the following people:
 Abraham Lempel and Jacob Ziv (for the LZ algorithm), Andrey Markov (for
 the definition of Markov chains), G.N.N. Martin (for the definition of
 range encoding), Igor Pavlov (for putting all the above together in
-LZMA), and Julian Seward (for bzip2's CLI and the idea of unzcrash).
+LZMA), and Julian Seward (for bzip2's CLI).
diff --git a/ChangeLog b/ChangeLog
index cc24306..edd72f5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2013-08-01  Antonio Diaz Diaz  <antonio@gnu.org>
+
+	* Version 1.15-rc1 released.
+	* main.cc (show_header): Do not show header version.
+	* Updated appendix 'Reference source code' to version 0.4 of lzd.
+	* Minor fixes.
+
 2013-07-15  Antonio Diaz Diaz  <antonio@gnu.org>
 
 	* Version 1.15-pre3 released.
@@ -11,7 +18,6 @@
 2013-03-21  Antonio Diaz Diaz  <ant_diaz@teleline.es>
 
 	* Version 1.15-pre1 released.
-	* Decompression time has been reduced by 1%.
 	* main.cc (show_header): Show header version if verbosity >= 4.
 	* Ignore option '-n, --threads' for compatibility with plzip.
 	* Added chapter 'Stream Format' and appendix 'Reference source code'
diff --git a/INSTALL b/INSTALL
index 9981a00..f8b14ab 100644
--- a/INSTALL
+++ b/INSTALL
@@ -10,9 +10,9 @@ Procedure
 ---------
 1. Unpack the archive if you have not done so already:
 
-	lzip -cd lzip[version].tar.lz | tar -xf -
+	tar -xf lzip[version].tar.lz
 or
-	gzip -cd lzip[version].tar.gz | tar -xf -
+	lzip -cd lzip[version].tar.lz | tar -xf -
 
 This creates the directory ./lzip[version] containing the source from
 the main archive.
diff --git a/NEWS b/NEWS
index 6f5ad8c..6c8d245 100644
--- a/NEWS
+++ b/NEWS
@@ -2,14 +2,12 @@ Changes in version 1.15:
 
 Lzip now shows the progress of compression at verbosity level 2 (-vv).
 
-Decompression time has been reduced by 1%.
-
-File version is now shown only if verbosity >= 4.
+Decompressing and testing no more show file version.
 
 Option "-n, --threads" is now accepted and ignored for compatibility
 with plzip.
 
 The configure script now accepts options with a separate argument.
 
-The chapter "Stream Format" and the appendix "Reference source code"
+The chapter "Stream format" and the appendix "Reference source code"
 have been added to the manual.
diff --git a/README b/README
index 4b8fae3..a47dd17 100644
--- a/README
+++ b/README
@@ -6,10 +6,6 @@ compresses more than bzip2, which makes it well suited for software
 distribution and data archiving. Lzip is a clean implementation of the
 LZMA algorithm.
 
-Lzip uses the same well-defined exit status values used by bzip2, which
-makes it safer when used in pipes or scripts than compressors returning
-ambiguous warning values, like gzip.
-
 The lzip file format is designed for long-term data archiving and
 provides very safe integrity checking. The member trailer stores the
 32-bit CRC of the original data, the size of the original data and the
@@ -26,7 +22,12 @@ recover the original uncompressed data.
 If you ever need to recover data from a damaged lzip file, try the
 lziprecover program. Lziprecover makes lzip files resistant to bit-flip
 (one of the most common forms of data corruption), and provides data
-recovery capabilities, including error-checked merging of damaged files.
+recovery capabilities, including error-checked merging of damaged copies
+of a file.
+
+Lzip uses the same well-defined exit status values used by bzip2, which
+makes it safer when used in pipes or scripts than compressors returning
+ambiguous warning values, like gzip.
 
 Lzip replaces every file given in the command line with a compressed
 version of itself, with the name "original_name.lz". Each compressed
@@ -53,7 +54,7 @@ multivolume compressed tar archives.
 
 Lzip is able to compress and decompress streams of unlimited size by
 automatically creating multi-member output. The members so created are
-large (about 2^60 bytes each).
+large, about 64 PiB each.
 
 Lzip will automatically use the smallest possible dictionary size
 without exceeding the given limit. Keep in mind that the decompression
@@ -72,7 +73,7 @@ The ideas embodied in lzip are due to (at least) the following people:
 Abraham Lempel and Jacob Ziv (for the LZ algorithm), Andrey Markov (for
 the definition of Markov chains), G.N.N. Martin (for the definition of
 range encoding), Igor Pavlov (for putting all the above together in
-LZMA), and Julian Seward (for bzip2's CLI and the idea of unzcrash).
+LZMA), and Julian Seward (for bzip2's CLI).
 
 
 Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
diff --git a/configure b/configure
index 1919c1b..ae61b04 100755
--- a/configure
+++ b/configure
@@ -6,9 +6,9 @@
 # to copy, distribute and modify it.
 
 pkgname=lzip
-pkgversion=1.15-pre3
+pkgversion=1.15-rc1
 progname=lzip
-srctrigger=doc/lzip.texinfo
+srctrigger=doc/${pkgname}.texinfo
 
 # clear some things potentially inherited from environment.
 LC_ALL=C
diff --git a/decoder.cc b/decoder.cc
index 6f1627c..b23daa2 100644
--- a/decoder.cc
+++ b/decoder.cc
@@ -107,7 +107,7 @@ void LZ_decoder::flush_data()
   const int size = pos - stream_pos;
   if( size > 0 )
     {
-    crc32.update( crc_, buffer + stream_pos, size );
+    crc32.update_buf( crc_, buffer + stream_pos, size );
     if( outfd >= 0 &&
         writeblock( outfd, buffer + stream_pos, size ) != size )
       throw Error( "Write error" );
@@ -203,7 +203,6 @@ int LZ_decoder::decode_member( const Pretty_print & pp )
   Bit_model bm_align[dis_align_size];
   Len_model match_len_model;
   Len_model rep_len_model;
-
   unsigned rep0 = 0;		// rep[0-3] latest four distances
   unsigned rep1 = 0;		// used for efficient coding of
   unsigned rep2 = 0;		// repeated distances
@@ -218,23 +217,23 @@ int LZ_decoder::decode_member( const Pretty_print & pp )
       {
       const uint8_t prev_byte = get_prev_byte();
       if( state.is_char() )
+        {
+        state.set_char1();
         put_byte( rdec.decode_tree( bm_literal[get_lit_state(prev_byte)], 8 ) );
+        }
       else
+        {
+        state.set_char2();
         put_byte( rdec.decode_matched( bm_literal[get_lit_state(prev_byte)],
                                        get_byte( rep0 ) ) );
-      state.set_char();
+        }
       }
     else
       {
       int len;
       if( rdec.decode_bit( bm_rep[state()] ) == 1 )		// 2nd bit
         {
-        if( rdec.decode_bit( bm_rep0[state()] ) == 0 )		// 3rd bit
-          {
-          if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
-            { state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
-          }
-        else
+        if( rdec.decode_bit( bm_rep0[state()] ) == 1 )		// 3rd bit
           {
           unsigned distance;
           if( rdec.decode_bit( bm_rep1[state()] ) == 0 )	// 4th bit
@@ -250,8 +249,13 @@ int LZ_decoder::decode_member( const Pretty_print & pp )
           rep1 = rep0;
           rep0 = distance;
           }
-        len = min_match_len + rdec.decode_len( rep_len_model, pos_state );
+        else
+          {
+          if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
+            { state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
+          }
         state.set_rep();
+        len = min_match_len + rdec.decode_len( rep_len_model, pos_state );
         }
       else
         {
diff --git a/decoder.h b/decoder.h
index 167a05e..6944dd1 100644
--- a/decoder.h
+++ b/decoder.h
@@ -273,7 +273,6 @@ public:
   ~LZ_decoder() { delete[] buffer; }
 
   unsigned crc() const { return crc_ ^ 0xFFFFFFFFU; }
-
   unsigned long long data_position() const { return partial_data_pos + pos; }
 
   int decode_member( const Pretty_print & pp );
diff --git a/doc/lzip.1 b/doc/lzip.1
index b7ea022..14654c2 100644
--- a/doc/lzip.1
+++ b/doc/lzip.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.37.1.
-.TH LZIP "1" "July 2013" "Lzip 1.15-pre3" "User Commands"
+.TH LZIP "1" "August 2013" "Lzip 1.15-rc1" "User Commands"
 .SH NAME
 Lzip \- reduces the size of files
 .SH SYNOPSIS
@@ -70,7 +70,8 @@ Ki = KiB = 2^10 = 1024, M = 10^6, Mi = 2^20, G = 10^9, Gi = 2^30, etc...
 The bidimensional parameter space of LZMA can't be mapped to a linear
 scale optimal for all files. If your files are large, very repetitive,
 etc, you may need to use the \fB\-\-match\-length\fR and \fB\-\-dictionary\-size\fR
-options directly to achieve optimal performance.
+options directly to achieve optimal performance. For example, \fB\-9m64\fR
+usually compresses executables more (and faster) than \fB\-9\fR.
 .PP
 Exit status: 0 for a normal exit, 1 for environmental problems (file
 not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or
diff --git a/doc/lzip.info b/doc/lzip.info
index 97d2bbb..4445d40 100644
--- a/doc/lzip.info
+++ b/doc/lzip.info
@@ -11,7 +11,7 @@ File: lzip.info,  Node: Top,  Next: Introduction,  Up: (dir)
 Lzip Manual
 ***********
 
-This manual is for Lzip (version 1.15-pre3, 15 July 2013).
+This manual is for Lzip (version 1.15-rc1, 1 August 2013).
 
 * Menu:
 
@@ -43,10 +43,6 @@ compresses more than bzip2, which makes it well suited for software
 distribution and data archiving. Lzip is a clean implementation of the
 LZMA algorithm.
 
-   Lzip uses the same well-defined exit status values used by bzip2,
-which makes it safer when used in pipes or scripts than compressors
-returning ambiguous warning values, like gzip.
-
    The lzip file format is designed for long-term data archiving and
 provides very safe integrity checking. The member trailer stores the
 32-bit CRC of the original data, the size of the original data and the
@@ -63,7 +59,12 @@ recover the original uncompressed data.
    If you ever need to recover data from a damaged lzip file, try the
 lziprecover program. Lziprecover makes lzip files resistant to bit-flip
 (one of the most common forms of data corruption), and provides data
-recovery capabilities, including error-checked merging of damaged files.
+recovery capabilities, including error-checked merging of damaged copies
+of a file.
+
+   Lzip uses the same well-defined exit status values used by bzip2,
+which makes it safer when used in pipes or scripts than compressors
+returning ambiguous warning values, like gzip.
 
    Lzip replaces every file given in the command line with a compressed
 version of itself, with the name "original_name.lz". Each compressed
@@ -90,7 +91,7 @@ multivolume compressed tar archives.
 
    Lzip is able to compress and decompress streams of unlimited size by
 automatically creating multi-member output. The members so created are
-large (about 2^60 bytes each).
+large, about 64 PiB each.
 
    The amount of memory required for compression is about 1 or 2 times
 the dictionary size limit (1 if input file size is less than dictionary
@@ -170,7 +171,7 @@ The ideas embodied in lzip are due to (at least) the following people:
 Abraham Lempel and Jacob Ziv (for the LZ algorithm), Andrey Markov (for
 the definition of Markov chains), G.N.N. Martin (for the definition of
 range encoding), Igor Pavlov (for putting all the above together in
-LZMA), and Julian Seward (for bzip2's CLI and the idea of unzcrash).
+LZMA), and Julian Seward (for bzip2's CLI).
 
 
 File: lzip.info,  Node: Invoking lzip,  Next: File format,  Prev: Algorithm,  Up: Top
@@ -194,10 +195,9 @@ The format for running lzip is:
 
 `-b BYTES'
 `--member-size=BYTES'
-     Produce a multi-member file and set the member size limit to BYTES.
-     Minimum member size limit is 100kB. Small member size may degrade
-     compression ratio, so use it only when needed. The default is to
-     produce single-member files.
+     Set the member size limit to BYTES. A small member size may
+     degrade compression ratio, so use it only when needed. Valid values
+     range from 100 kB to 64 PiB. Defaults to 64 PiB.
 
 `-c'
 `--stdout'
@@ -246,8 +246,8 @@ The format for running lzip is:
 
 `-s BYTES'
 `--dictionary-size=BYTES'
-     Set the dictionary size limit in bytes. Valid values range from
-     4KiB to 512MiB. Lzip will use the smallest possible dictionary
+     Set the dictionary size limit in bytes. Valid values range from 4
+     KiB to 512 MiB. Lzip will use the smallest possible dictionary
      size for each member without exceeding this limit. Note that
      dictionary sizes are quantized. If the specified size does not
      match one of the valid sizes, it will be rounded upwards by adding
@@ -263,9 +263,9 @@ The format for running lzip is:
      Split the compressed output into several volume files with names
      `original_name00001.lz', `original_name00002.lz', etc, and set the
      volume size limit to BYTES. Each volume is a complete, maybe
-     multi-member, lzip file. Minimum volume size limit is 100kB. Small
-     volume size may degrade compression ratio, so use it only when
-     needed.
+     multi-member, lzip file. A small volume size may degrade
+     compression ratio, so use it only when needed. Valid values range
+     from 100 kB to 4 EiB.
 
 `-t'
 `--test'
@@ -293,7 +293,8 @@ The format for running lzip is:
      linear scale optimal for all files. If your files are large, very
      repetitive, etc, you may need to use the `--match-length' and
      `--dictionary-size' options directly to achieve optimal
-     performance.
+     performance. For example, `-9m64' usually compresses executables
+     more (and faster) than `-9'.
 
      Level   Dictionary size   Match length limit
      -0      64 KiB            16 bytes
@@ -312,7 +313,6 @@ The format for running lzip is:
      Aliases for GNU gzip compatibility.
 
 
-
    Numbers given as arguments to options may be followed by a multiplier
 and an optional `B' for "byte".
 
@@ -371,7 +371,7 @@ additional information before, between, or after them.
 
 `ID string'
      A four byte string, identifying the lzip format, with the value
-     "LZIP".
+     "LZIP" (0x4C, 0x5A, 0x49, 0x50).
 
 `VN (version number, 1 byte)'
      Just in case something needs to be modified in the future. 1 for
@@ -386,12 +386,13 @@ additional information before, between, or after them.
      Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).
      Bits 7-5 contain the number of wedges (0 to 7) to substract from
      the base size to obtain the dictionary size.
-     Example: 0xD3 = (2^19 - 6 * 2^15) = (512KiB - 6 * 32KiB) = 320KiB
-     Valid values for dictionary size range from 4KiB to 512MiB.
+     Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB
+     Valid values for dictionary size range from 4 KiB to 512 MiB.
 
 `Lzma stream'
      The lzma stream, finished by an end of stream marker. Uses default
-     values for encoder properties.
+     values for encoder properties. See the chapter `Stream format'
+     (*note Stream format::) for a complete description.
 
 `CRC32 (4 bytes)'
      CRC of the uncompressed original data.
@@ -508,8 +509,9 @@ integers representing the probability of the corresponding bit being 0.
    The indices used in these arrays are:
 
 `state'
-     A state machine (`State' in the source) coding the latest 2 to 4
-     types of sequences processed. The initial state is 0.
+     A state machine (`State' in the source) with 12 states (0 to 11),
+     coding the latest 2 to 4 types of sequences processed. The initial
+     state is 0.
 
 `pos_state'
      Value of the 2 least significant bits of the current position in
@@ -523,6 +525,26 @@ integers representing the probability of the corresponding bit being 0.
      resulting value is in the range 0 to 3.
 
 
+   In the following table, `!literal' is any sequence except a literal
+byte. `rep' is any one of `rep0', `rep1', `rep2' or `rep3'. The types
+of previous sequences corresponding to each state are:
+
+State   Types of previous sequences
+---------------------------------------------- 
+0       literal, literal, literal
+1       match, literal, literal
+2       (rep or shortrep), literal, literal
+3       literal, shortrep, literal, literal
+4       match, literal
+5       (rep or shortrep), literal
+6       literal, shortrep, literal
+7       literal, match
+8       literal, rep
+9       literal, shortrep
+10      !literal, match
+11      !literal, (rep or shortrep)
+
+
    The contexts for decoding the type of coding sequence are:
 
 Name           Indices                       Used when
@@ -619,7 +641,7 @@ and show the compression ratio.
 
 
 Example 2: Like example 1 but the created `file.lz' is multi-member
-with a member size of 1MiB. The compression ratio is not shown.
+with a member size of 1 MiB. The compression ratio is not shown.
 
      lzip -b 1MiB file
 
@@ -642,7 +664,7 @@ Example 5: Compress a whole floppy in /dev/fd0 and send the output to
      lzip -c /dev/fd0 > file.lz
 
 
-Example 6: Decompress `file.lz' partially until 10KiB of decompressed
+Example 6: Decompress `file.lz' partially until 10 KiB of decompressed
 data are produced.
 
      lzip -cd file.lz | dd bs=1024 count=10
@@ -655,7 +677,7 @@ to decompressed byte 15000 (5000 bytes are produced).
 
 
 Example 8: Create a multivolume compressed tar archive with a volume
-size of 1440KiB.
+size of 1440 KiB.
 
      tar -c some_directory | lzip -S 1440KiB -o volume_name
 
@@ -665,9 +687,9 @@ Example 9: Extract a multivolume compressed tar archive.
      lzip -cd volume_name*.lz | tar -xf -
 
 
-Example 10: Create a multivolume compressed backup of a big database
-file with a volume size of 650MB, where each volume is a multi-member
-file with a member size of 32MiB.
+Example 10: Create a multivolume compressed backup of a large database
+file with a volume size of 650 MB, where each volume is a multi-member
+file with a member size of 32 MiB.
 
      lzip -b 32MiB -S 650MB big_db
 
@@ -692,6 +714,22 @@ File: lzip.info,  Node: Reference source code,  Next: Concept index,  Prev: Prob
 Appendix A Reference source code
 ********************************
 
+/*  Lzd - Educational decompressor for lzip files
+    Copyright (C) 2013 Antonio Diaz Diaz.
+
+    This program is free software: you have unlimited permission
+    to copy, distribute and modify it.
+
+    This program 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.
+*/
+/*
+    Exit status: 0 for a normal exit, 1 for environmental problems
+    (file not found, invalid flags, I/O errors, etc), 2 to indicate a
+    corrupt or invalid input file.
+*/
+
 #include <algorithm>
 #include <cerrno>
 #include <cstdio>
@@ -716,20 +754,20 @@ public:
     static const int next[states] = { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 };
     st = next[st];
     }
-
-  void set_match()     { st = ( ( st < 7 ) ? 7 : 10 ); }
-  void set_rep()       { st = ( ( st < 7 ) ? 8 : 11 ); }
-  void set_short_rep() { st = ( ( st < 7 ) ? 9 : 11 ); }
+  void set_match()     { st = ( st < 7 ) ? 7 : 10; }
+  void set_rep()       { st = ( st < 7 ) ? 8 : 11; }
+  void set_short_rep() { st = ( st < 7 ) ? 9 : 11; }
   };
 
 
 enum {
+  min_dictionary_size = 1 << 12,
+  max_dictionary_size = 1 << 29,
   literal_context_bits = 3,
   pos_state_bits = 2,
   pos_states = 1 << pos_state_bits,
   pos_state_mask = pos_states - 1,
 
-  max_dis_states = 4,
   dis_slot_bits = 6,
   start_dis_model = 4,
   end_dis_model = 14,
@@ -744,13 +782,14 @@ enum {
   len_mid_symbols = 1 << len_mid_bits,
   len_high_symbols = 1 << len_high_bits,
   max_len_symbols = len_low_symbols + len_mid_symbols + len_high_symbols,
+
   min_match_len = 2,					// must be 2
+  max_dis_states = 4,
 
   bit_model_move_bits = 5,
   bit_model_total_bits = 11,
   bit_model_total = 1 << bit_model_total_bits };
 
-
 struct Bit_model
   {
   int probability;
@@ -767,6 +806,40 @@ struct Len_model
   };
 
 
+class CRC32
+  {
+  uint32_t data[256];		// Table of CRCs of all 8-bit messages.
+
+public:
+  CRC32()
+    {
+    for( unsigned n = 0; n < 256; ++n )
+      {
+      unsigned c = n;
+      for( int k = 0; k < 8; ++k )
+        { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; }
+      data[n] = c;
+      }
+    }
+
+  void update_buf( uint32_t & crc, const uint8_t * const buffer,
+                   const int size ) const
+    {
+    for( int i = 0; i < size; ++i )
+      crc = data[(crc^buffer[i])&0xFF] ^ ( crc >> 8 );
+    }
+  };
+
+const CRC32 crc32;
+
+
+typedef uint8_t File_header[6];	// 0-3 magic, 4 version, 5 coded_dict_size
+
+typedef uint8_t File_trailer[20];
+			//  0-3  CRC32 of the uncompressed data
+			//  4-11 size of the uncompressed data
+			// 12-19 member size including header and trailer
+
 class Range_decoder
   {
   uint32_t code;
@@ -775,9 +848,11 @@ class Range_decoder
 public:
   Range_decoder() : code( 0 ), range( 0xFFFFFFFFU )
     {
-    for( int i = 0; i < 5; ++i ) code = (code << 8) | std::getc( stdin );
+    for( int i = 0; i < 5; ++i ) code = (code << 8) | get_byte();
     }
 
+  uint8_t get_byte() { return std::getc( stdin ); }
+
   int decode( const int num_bits )
     {
     int symbol = 0;
@@ -787,7 +862,7 @@ public:
       symbol <<= 1;
       if( code >= range ) { code -= range; symbol |= 1; }
       if( range <= 0x00FFFFFFU )			// normalize
-        { range <<= 8; code = (code << 8) | std::getc( stdin ); }
+        { range <<= 8; code = (code << 8) | get_byte(); }
       }
     return symbol;
     }
@@ -810,7 +885,7 @@ public:
       symbol = 1;
       }
     if( range <= 0x00FFFFFFU )				// normalize
-      { range <<= 8; code = (code << 8) | std::getc( stdin ); }
+      { range <<= 8; code = (code << 8) | get_byte(); }
     return symbol;
     }
 
@@ -856,12 +931,11 @@ public:
   int decode_len( Len_model & lm, const int pos_state )
     {
     if( decode_bit( lm.choice1 ) == 0 )
-      return min_match_len +
-             decode_tree( lm.bm_low[pos_state], len_low_bits );
+      return decode_tree( lm.bm_low[pos_state], len_low_bits );
     if( decode_bit( lm.choice2 ) == 0 )
-      return min_match_len + len_low_symbols +
+      return len_low_symbols +
              decode_tree( lm.bm_mid[pos_state], len_mid_bits );
-    return min_match_len + len_low_symbols + len_mid_symbols +
+    return len_low_symbols + len_mid_symbols +
            decode_tree( lm.bm_high, len_high_bits );
     }
   };
@@ -881,8 +955,8 @@ class LZ_decoder
 
   uint8_t get_byte( const unsigned distance ) const
     {
-    int i = pos - distance - 1;
-    if( i < 0 ) i += dictionary_size;
+    unsigned i = pos - distance - 1;
+    if( pos <= distance ) i += dictionary_size;
     return buffer[i];
     }
 
@@ -912,38 +986,12 @@ public:
   };
 
 
-class CRC32
-  {
-  uint32_t data[256];		// Table of CRCs of all 8-bit messages.
-
-public:
-  CRC32()
-    {
-    for( unsigned n = 0; n < 256; ++n )
-      {
-      unsigned c = n;
-      for( int k = 0; k < 8; ++k )
-        { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; }
-      data[n] = c;
-      }
-    }
-
-  void update( uint32_t & crc, const uint8_t * buffer, const int size ) const
-    {
-    for( int i = 0; i < size; ++i )
-      crc = data[(crc^buffer[i])&0xFF] ^ ( crc >> 8 );
-    }
-  };
-
-const CRC32 crc32;
-
-
 void LZ_decoder::flush_data()
   {
   if( pos > stream_pos )
     {
     const unsigned size = pos - stream_pos;
-    crc32.update( crc_, buffer + stream_pos, size );
+    crc32.update_buf( crc_, buffer + stream_pos, size );
     errno = 0;
     if( std::fwrite( buffer + stream_pos, 1, size, stdout ) != size )
       { std::fprintf( stderr, "Write error: %s\n", std::strerror( errno ) );
@@ -993,12 +1041,7 @@ bool LZ_decoder::decode_member()		// Returns false if error
       int len;
       if( rdec.decode_bit( bm_rep[state()] ) == 1 )		// 2nd bit
         {
-        if( rdec.decode_bit( bm_rep0[state()] ) == 0 )		// 3rd bit
-          {
-          if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
-            { state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
-          }
-        else
+        if( rdec.decode_bit( bm_rep0[state()] ) == 1 )		// 3rd bit
           {
           unsigned distance;
           if( rdec.decode_bit( bm_rep1[state()] ) == 0 )	// 4th bit
@@ -1014,13 +1057,18 @@ bool LZ_decoder::decode_member()		// Returns false if error
           rep1 = rep0;
           rep0 = distance;
           }
-        len = rdec.decode_len( rep_len_model, pos_state );
+        else
+          {
+          if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
+            { state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
+          }
+        len = min_match_len + rdec.decode_len( rep_len_model, pos_state );
         state.set_rep();
         }
       else
         {
         rep3 = rep2; rep2 = rep1; rep1 = rep0;
-        len = rdec.decode_len( match_len_model, pos_state );
+        len = min_match_len + rdec.decode_len( match_len_model, pos_state );
         const int dis_state = std::min( len - min_match_len, max_dis_states - 1 );
         const int dis_slot =
           rdec.decode_tree( bm_dis_slot[dis_state], dis_slot_bits );
@@ -1055,46 +1103,25 @@ bool LZ_decoder::decode_member()		// Returns false if error
   }
 
 
-enum { min_dictionary_size = 1 << 12,
-       max_dictionary_size = 1 << 29 };
-
-typedef uint8_t File_header[6];	// 0-3 magic, 4 version, 5 coded_dict_size
-
-typedef uint8_t File_trailer[20];
-			//  0-3  CRC32 of the uncompressed data
-			//  4-11 size of the uncompressed data
-			// 12-19 member size including header and trailer
-
-
-/*  Exit status: 0 for a normal exit, 1 for environmental problems
-    (file not found, invalid flags, I/O errors, etc), 2 to indicate a
-    corrupt or invalid input file. */
-
 int main( const int argc, const char * const argv[] )
   {
   if( argc > 1 )
     {
     std::printf( "Lzd %s - Educational decompressor for lzip files.\n",
                  PROGVERSION );
-    std::printf( "Study the source to learn how a simple lzip decompressor works.\n"
-                 "It is not safe to use it for any real work.\n"
+    std::printf( "Study the source to learn how a lzip decompressor works.\n"
+                 "See the lzip manual for an explanation of the code.\n"
+                 "It is not safe to use lzd for any real work.\n"
                  "\nUsage: %s < file.lz > file\n", argv[0] );
     std::printf( "Lzd decompresses from standard input to standard output.\n"
                  "\nCopyright (C) 2013 Antonio Diaz Diaz.\n"
                  "This is free software: you are free to change and redistribute it.\n"
                  "There is NO WARRANTY, to the extent permitted by law.\n"
                  "Report bugs to lzip-bug@nongnu.org\n"
-                 "Lzip home page: http://www.nongnu.org/lzip/lzip.html\n" );
+                 "Lzd home page: http://www.nongnu.org/lzip/lzd.html\n" );
     return 0;
     }
 
-  if( isatty( STDIN_FILENO ) )
-    {
-    std::fprintf( stderr, "I won't read compressed data from a terminal.\n"
-                          "Try '%s --help' for more information.\n", argv[0] );
-    return 1;
-    }
-
   for( bool first_member = true; ; first_member = false )
     {
     File_header header;
@@ -1166,14 +1193,14 @@ Concept index
 Tag Table:
 Node: Top210
 Node: Introduction1052
-Node: Algorithm5006
-Node: Invoking lzip7524
-Node: File format13162
-Node: Stream format15595
-Node: Examples24309
-Node: Problems26258
-Node: Reference source code26788
-Node: Concept index40035
+Node: Algorithm5012
+Node: Invoking lzip7505
+Node: File format13181
+Node: Stream format15729
+Node: Examples25134
+Node: Problems27090
+Node: Reference source code27620
+Node: Concept index41135
 
 End Tag Table
 
diff --git a/doc/lzip.texinfo b/doc/lzip.texinfo
index 1c04f2c..0e8ac92 100644
--- a/doc/lzip.texinfo
+++ b/doc/lzip.texinfo
@@ -6,8 +6,8 @@
 @finalout
 @c %**end of header
 
-@set UPDATED 15 July 2013
-@set VERSION 1.15-pre3
+@set UPDATED 1 August 2013
+@set VERSION 1.15-rc1
 
 @dircategory Data Compression
 @direntry
@@ -64,10 +64,6 @@ compresses more than bzip2, which makes it well suited for software
 distribution and data archiving. Lzip is a clean implementation of the
 LZMA algorithm.
 
-Lzip uses the same well-defined exit status values used by bzip2, which
-makes it safer when used in pipes or scripts than compressors returning
-ambiguous warning values, like gzip.
-
 The lzip file format is designed for long-term data archiving and
 provides very safe integrity checking. The member trailer stores the
 32-bit CRC of the original data, the size of the original data and the
@@ -84,7 +80,12 @@ recover the original uncompressed data.
 If you ever need to recover data from a damaged lzip file, try the
 lziprecover program. Lziprecover makes lzip files resistant to bit-flip
 (one of the most common forms of data corruption), and provides data
-recovery capabilities, including error-checked merging of damaged files.
+recovery capabilities, including error-checked merging of damaged copies
+of a file.
+
+Lzip uses the same well-defined exit status values used by bzip2, which
+makes it safer when used in pipes or scripts than compressors returning
+ambiguous warning values, like gzip.
 
 Lzip replaces every file given in the command line with a compressed
 version of itself, with the name "original_name.lz". Each compressed
@@ -111,7 +112,7 @@ multivolume compressed tar archives.
 
 Lzip is able to compress and decompress streams of unlimited size by
 automatically creating multi-member output. The members so created are
-large (about 2^60 bytes each).
+large, about 64 PiB each.
 
 The amount of memory required for compression is about 1 or 2 times the
 dictionary size limit (1 if input file size is less than dictionary size
@@ -193,7 +194,7 @@ The ideas embodied in lzip are due to (at least) the following people:
 Abraham Lempel and Jacob Ziv (for the LZ algorithm), Andrey Markov (for
 the definition of Markov chains), G.N.N. Martin (for the definition of
 range encoding), Igor Pavlov (for putting all the above together in
-LZMA), and Julian Seward (for bzip2's CLI and the idea of unzcrash).
+LZMA), and Julian Seward (for bzip2's CLI).
 
 
 @node Invoking lzip
@@ -222,10 +223,9 @@ Print the version number of lzip on the standard output and exit.
 
 @item -b @var{bytes}
 @itemx --member-size=@var{bytes}
-Produce a multi-member file and set the member size limit to @var{bytes}.
-Minimum member size limit is 100kB. Small member size may degrade
-compression ratio, so use it only when needed. The default is to produce
-single-member files.
+Set the member size limit to @var{bytes}. A small member size may
+degrade compression ratio, so use it only when needed. Valid values
+range from 100 kB to 64 PiB. Defaults to 64 PiB.
 
 @item -c
 @itemx --stdout
@@ -271,8 +271,8 @@ Quiet operation. Suppress all messages.
 
 @item -s @var{bytes}
 @itemx --dictionary-size=@var{bytes}
-Set the dictionary size limit in bytes. Valid values range from 4KiB to
-512MiB. Lzip will use the smallest possible dictionary size for each
+Set the dictionary size limit in bytes. Valid values range from 4 KiB to
+512 MiB. Lzip will use the smallest possible dictionary size for each
 member without exceeding this limit. Note that dictionary sizes are
 quantized. If the specified size does not match one of the valid sizes,
 it will be rounded upwards by adding up to (@var{bytes} / 16) to it.
@@ -286,8 +286,9 @@ is affected at compression time by the choice of dictionary size limit.
 Split the compressed output into several volume files with names
 @samp{original_name00001.lz}, @samp{original_name00002.lz}, etc, and set
 the volume size limit to @var{bytes}. Each volume is a complete, maybe
-multi-member, lzip file. Minimum volume size limit is 100kB. Small volume
-size may degrade compression ratio, so use it only when needed.
+multi-member, lzip file. A small volume size may degrade compression
+ratio, so use it only when needed. Valid values range from 100 kB to 4
+EiB.
 
 @item -t
 @itemx --test
@@ -314,7 +315,8 @@ The bidimensional parameter space of LZMA can't be mapped to a linear
 scale optimal for all files. If your files are large, very repetitive,
 etc, you may need to use the @samp{--match-length} and
 @samp{--dictionary-size} options directly to achieve optimal
-performance.
+performance. For example, @samp{-9m64} usually compresses executables
+more (and faster) than @samp{-9}.
 
 @multitable {Level} {Dictionary size} {Match length limit}
 @item Level @tab Dictionary size @tab Match length limit
@@ -336,7 +338,6 @@ Aliases for GNU gzip compatibility.
 
 @end table
 
-@sp 1
 Numbers given as arguments to options may be followed by a multiplier
 and an optional @samp{B} for "byte".
 
@@ -402,7 +403,8 @@ All multibyte values are stored in little endian order.
 
 @table @samp
 @item ID string
-A four byte string, identifying the lzip format, with the value "LZIP".
+A four byte string, identifying the lzip format, with the value "LZIP"
+(0x4C, 0x5A, 0x49, 0x50).
 
 @item VN (version number, 1 byte)
 Just in case something needs to be modified in the future. 1 for now.
@@ -415,12 +417,13 @@ wedges between 0 and 7. The size of a wedge is (base_size / 16).@*
 Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).@*
 Bits 7-5 contain the number of wedges (0 to 7) to substract from the
 base size to obtain the dictionary size.@*
-Example: 0xD3 = (2^19 - 6 * 2^15) = (512KiB - 6 * 32KiB) = 320KiB@*
-Valid values for dictionary size range from 4KiB to 512MiB.
+Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB@*
+Valid values for dictionary size range from 4 KiB to 512 MiB.
 
 @item Lzma stream
-The lzma stream, finished by an end of stream marker. Uses default values
-for encoder properties.
+The lzma stream, finished by an end of stream marker. Uses default
+values for encoder properties. See the chapter @samp{Stream format}
+(@pxref{Stream format}) for a complete description.
 
 @item CRC32 (4 bytes)
 CRC of the uncompressed original data.
@@ -540,9 +543,9 @@ The indices used in these arrays are:
 
 @table @samp
 @item state
-
-A state machine (@samp{State} in the source) coding the latest 2 to 4
-types of sequences processed. The initial state is 0.
+A state machine (@samp{State} in the source) with 12 states (0 to 11),
+coding the latest 2 to 4 types of sequences processed. The initial state
+is 0.
 
 @item pos_state
 Value of the 2 least significant bits of the current position in the
@@ -558,6 +561,28 @@ resulting value is in the range 0 to 3.
 @end table
 
 
+In the following table, @samp{!literal} is any sequence except a literal
+byte. @samp{rep} is any one of @samp{rep0}, @samp{rep1}, @samp{rep2} or
+@samp{rep3}. The types of previous sequences corresponding to each state
+are:
+
+@multitable {State} {literal, shortrep, literal, literal}
+@headitem State @tab Types of previous sequences
+@item  0 @tab literal, literal, literal
+@item  1 @tab match, literal, literal
+@item  2 @tab (rep or shortrep), literal, literal
+@item  3 @tab literal, shortrep, literal, literal
+@item  4 @tab match, literal
+@item  5 @tab (rep or shortrep), literal
+@item  6 @tab literal, shortrep, literal
+@item  7 @tab literal, match
+@item  8 @tab literal, rep
+@item  9 @tab literal, shortrep
+@item 10 @tab !literal, match
+@item 11 @tab !literal, (rep or shortrep)
+@end multitable
+
+@sp 1
 The contexts for decoding the type of coding sequence are:
 
 @multitable @columnfractions .2 .4 .4
@@ -659,7 +684,7 @@ lzip -v file
 @sp 1
 @noindent
 Example 2: Like example 1 but the created @samp{file.lz} is multi-member
-with a member size of 1MiB. The compression ratio is not shown.
+with a member size of 1 MiB. The compression ratio is not shown.
 
 @example
 lzip -b 1MiB file
@@ -695,7 +720,7 @@ lzip -c /dev/fd0 > file.lz
 
 @sp 1
 @noindent
-Example 6: Decompress @samp{file.lz} partially until 10KiB of
+Example 6: Decompress @samp{file.lz} partially until 10 KiB of
 decompressed data are produced.
 
 @example
@@ -714,7 +739,7 @@ lzip -cd file.lz | dd bs=1000 skip=10 count=5
 @sp 1
 @noindent
 Example 8: Create a multivolume compressed tar archive with a volume
-size of 1440KiB.
+size of 1440 KiB.
 
 @example
 tar -c some_directory | lzip -S 1440KiB -o volume_name
@@ -730,9 +755,9 @@ lzip -cd volume_name*.lz | tar -xf -
 
 @sp 1
 @noindent
-Example 10: Create a multivolume compressed backup of a big database
-file with a volume size of 650MB, where each volume is a multi-member
-file with a member size of 32MiB.
+Example 10: Create a multivolume compressed backup of a large database
+file with a volume size of 650 MB, where each volume is a multi-member
+file with a member size of 32 MiB.
 
 @example
 lzip -b 32MiB -S 650MB big_db
@@ -759,6 +784,22 @@ find by running @w{@samp{lzip --version}}.
 @cindex reference source code
 
 @verbatim
+/*  Lzd - Educational decompressor for lzip files
+    Copyright (C) 2013 Antonio Diaz Diaz.
+
+    This program is free software: you have unlimited permission
+    to copy, distribute and modify it.
+
+    This program 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.
+*/
+/*
+    Exit status: 0 for a normal exit, 1 for environmental problems
+    (file not found, invalid flags, I/O errors, etc), 2 to indicate a
+    corrupt or invalid input file.
+*/
+
 #include <algorithm>
 #include <cerrno>
 #include <cstdio>
@@ -783,20 +824,20 @@ public:
     static const int next[states] = { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 };
     st = next[st];
     }
-
-  void set_match()     { st = ( ( st < 7 ) ? 7 : 10 ); }
-  void set_rep()       { st = ( ( st < 7 ) ? 8 : 11 ); }
-  void set_short_rep() { st = ( ( st < 7 ) ? 9 : 11 ); }
+  void set_match()     { st = ( st < 7 ) ? 7 : 10; }
+  void set_rep()       { st = ( st < 7 ) ? 8 : 11; }
+  void set_short_rep() { st = ( st < 7 ) ? 9 : 11; }
   };
 
 
 enum {
+  min_dictionary_size = 1 << 12,
+  max_dictionary_size = 1 << 29,
   literal_context_bits = 3,
   pos_state_bits = 2,
   pos_states = 1 << pos_state_bits,
   pos_state_mask = pos_states - 1,
 
-  max_dis_states = 4,
   dis_slot_bits = 6,
   start_dis_model = 4,
   end_dis_model = 14,
@@ -811,13 +852,14 @@ enum {
   len_mid_symbols = 1 << len_mid_bits,
   len_high_symbols = 1 << len_high_bits,
   max_len_symbols = len_low_symbols + len_mid_symbols + len_high_symbols,
+
   min_match_len = 2,					// must be 2
+  max_dis_states = 4,
 
   bit_model_move_bits = 5,
   bit_model_total_bits = 11,
   bit_model_total = 1 << bit_model_total_bits };
 
-
 struct Bit_model
   {
   int probability;
@@ -834,6 +876,40 @@ struct Len_model
   };
 
 
+class CRC32
+  {
+  uint32_t data[256];		// Table of CRCs of all 8-bit messages.
+
+public:
+  CRC32()
+    {
+    for( unsigned n = 0; n < 256; ++n )
+      {
+      unsigned c = n;
+      for( int k = 0; k < 8; ++k )
+        { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; }
+      data[n] = c;
+      }
+    }
+
+  void update_buf( uint32_t & crc, const uint8_t * const buffer,
+                   const int size ) const
+    {
+    for( int i = 0; i < size; ++i )
+      crc = data[(crc^buffer[i])&0xFF] ^ ( crc >> 8 );
+    }
+  };
+
+const CRC32 crc32;
+
+
+typedef uint8_t File_header[6];	// 0-3 magic, 4 version, 5 coded_dict_size
+
+typedef uint8_t File_trailer[20];
+			//  0-3  CRC32 of the uncompressed data
+			//  4-11 size of the uncompressed data
+			// 12-19 member size including header and trailer
+
 class Range_decoder
   {
   uint32_t code;
@@ -842,9 +918,11 @@ class Range_decoder
 public:
   Range_decoder() : code( 0 ), range( 0xFFFFFFFFU )
     {
-    for( int i = 0; i < 5; ++i ) code = (code << 8) | std::getc( stdin );
+    for( int i = 0; i < 5; ++i ) code = (code << 8) | get_byte();
     }
 
+  uint8_t get_byte() { return std::getc( stdin ); }
+
   int decode( const int num_bits )
     {
     int symbol = 0;
@@ -854,7 +932,7 @@ public:
       symbol <<= 1;
       if( code >= range ) { code -= range; symbol |= 1; }
       if( range <= 0x00FFFFFFU )			// normalize
-        { range <<= 8; code = (code << 8) | std::getc( stdin ); }
+        { range <<= 8; code = (code << 8) | get_byte(); }
       }
     return symbol;
     }
@@ -877,7 +955,7 @@ public:
       symbol = 1;
       }
     if( range <= 0x00FFFFFFU )				// normalize
-      { range <<= 8; code = (code << 8) | std::getc( stdin ); }
+      { range <<= 8; code = (code << 8) | get_byte(); }
     return symbol;
     }
 
@@ -923,12 +1001,11 @@ public:
   int decode_len( Len_model & lm, const int pos_state )
     {
     if( decode_bit( lm.choice1 ) == 0 )
-      return min_match_len +
-             decode_tree( lm.bm_low[pos_state], len_low_bits );
+      return decode_tree( lm.bm_low[pos_state], len_low_bits );
     if( decode_bit( lm.choice2 ) == 0 )
-      return min_match_len + len_low_symbols +
+      return len_low_symbols +
              decode_tree( lm.bm_mid[pos_state], len_mid_bits );
-    return min_match_len + len_low_symbols + len_mid_symbols +
+    return len_low_symbols + len_mid_symbols +
            decode_tree( lm.bm_high, len_high_bits );
     }
   };
@@ -948,8 +1025,8 @@ class LZ_decoder
 
   uint8_t get_byte( const unsigned distance ) const
     {
-    int i = pos - distance - 1;
-    if( i < 0 ) i += dictionary_size;
+    unsigned i = pos - distance - 1;
+    if( pos <= distance ) i += dictionary_size;
     return buffer[i];
     }
 
@@ -979,38 +1056,12 @@ public:
   };
 
 
-class CRC32
-  {
-  uint32_t data[256];		// Table of CRCs of all 8-bit messages.
-
-public:
-  CRC32()
-    {
-    for( unsigned n = 0; n < 256; ++n )
-      {
-      unsigned c = n;
-      for( int k = 0; k < 8; ++k )
-        { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; }
-      data[n] = c;
-      }
-    }
-
-  void update( uint32_t & crc, const uint8_t * buffer, const int size ) const
-    {
-    for( int i = 0; i < size; ++i )
-      crc = data[(crc^buffer[i])&0xFF] ^ ( crc >> 8 );
-    }
-  };
-
-const CRC32 crc32;
-
-
 void LZ_decoder::flush_data()
   {
   if( pos > stream_pos )
     {
     const unsigned size = pos - stream_pos;
-    crc32.update( crc_, buffer + stream_pos, size );
+    crc32.update_buf( crc_, buffer + stream_pos, size );
     errno = 0;
     if( std::fwrite( buffer + stream_pos, 1, size, stdout ) != size )
       { std::fprintf( stderr, "Write error: %s\n", std::strerror( errno ) );
@@ -1060,12 +1111,7 @@ bool LZ_decoder::decode_member()		// Returns false if error
       int len;
       if( rdec.decode_bit( bm_rep[state()] ) == 1 )		// 2nd bit
         {
-        if( rdec.decode_bit( bm_rep0[state()] ) == 0 )		// 3rd bit
-          {
-          if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
-            { state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
-          }
-        else
+        if( rdec.decode_bit( bm_rep0[state()] ) == 1 )		// 3rd bit
           {
           unsigned distance;
           if( rdec.decode_bit( bm_rep1[state()] ) == 0 )	// 4th bit
@@ -1081,13 +1127,18 @@ bool LZ_decoder::decode_member()		// Returns false if error
           rep1 = rep0;
           rep0 = distance;
           }
-        len = rdec.decode_len( rep_len_model, pos_state );
+        else
+          {
+          if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
+            { state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
+          }
+        len = min_match_len + rdec.decode_len( rep_len_model, pos_state );
         state.set_rep();
         }
       else
         {
         rep3 = rep2; rep2 = rep1; rep1 = rep0;
-        len = rdec.decode_len( match_len_model, pos_state );
+        len = min_match_len + rdec.decode_len( match_len_model, pos_state );
         const int dis_state = std::min( len - min_match_len, max_dis_states - 1 );
         const int dis_slot =
           rdec.decode_tree( bm_dis_slot[dis_state], dis_slot_bits );
@@ -1122,46 +1173,25 @@ bool LZ_decoder::decode_member()		// Returns false if error
   }
 
 
-enum { min_dictionary_size = 1 << 12,
-       max_dictionary_size = 1 << 29 };
-
-typedef uint8_t File_header[6];	// 0-3 magic, 4 version, 5 coded_dict_size
-
-typedef uint8_t File_trailer[20];
-			//  0-3  CRC32 of the uncompressed data
-			//  4-11 size of the uncompressed data
-			// 12-19 member size including header and trailer
-
-
-/*  Exit status: 0 for a normal exit, 1 for environmental problems
-    (file not found, invalid flags, I/O errors, etc), 2 to indicate a
-    corrupt or invalid input file. */
-
 int main( const int argc, const char * const argv[] )
   {
   if( argc > 1 )
     {
     std::printf( "Lzd %s - Educational decompressor for lzip files.\n",
                  PROGVERSION );
-    std::printf( "Study the source to learn how a simple lzip decompressor works.\n"
-                 "It is not safe to use it for any real work.\n"
+    std::printf( "Study the source to learn how a lzip decompressor works.\n"
+                 "See the lzip manual for an explanation of the code.\n"
+                 "It is not safe to use lzd for any real work.\n"
                  "\nUsage: %s < file.lz > file\n", argv[0] );
     std::printf( "Lzd decompresses from standard input to standard output.\n"
                  "\nCopyright (C) 2013 Antonio Diaz Diaz.\n"
                  "This is free software: you are free to change and redistribute it.\n"
                  "There is NO WARRANTY, to the extent permitted by law.\n"
                  "Report bugs to lzip-bug@nongnu.org\n"
-                 "Lzip home page: http://www.nongnu.org/lzip/lzip.html\n" );
+                 "Lzd home page: http://www.nongnu.org/lzip/lzd.html\n" );
     return 0;
     }
 
-  if( isatty( STDIN_FILENO ) )
-    {
-    std::fprintf( stderr, "I won't read compressed data from a terminal.\n"
-                          "Try '%s --help' for more information.\n", argv[0] );
-    return 1;
-    }
-
   for( bool first_member = true; ; first_member = false )
     {
     File_header header;
diff --git a/encoder.cc b/encoder.cc
index 0876742..cc43337 100644
--- a/encoder.cc
+++ b/encoder.cc
@@ -101,8 +101,8 @@ Matchfinder_base::Matchfinder_base( const int before, const int dict_size,
     dictionary_size_ = dict_size;
   pos_limit = buffer_size;
   if( !at_stream_end ) pos_limit -= after_size;
-  int size = 1 << std::max( 16, real_bits( dictionary_size_ - 1 ) - 2 );
-  if( dictionary_size_ > 1 << 26 )
+  unsigned size = 1 << std::max( 16, real_bits( dictionary_size_ - 1 ) - 2 );
+  if( dictionary_size_ > 1 << 26 )		// 64 MiB
     size >>= 1;
   key4_mask = size - 1;
   size += num_prev_positions23;
@@ -336,7 +336,7 @@ void LZ_encoder::fill_distance_prices()
 
 
 // Return value == number of bytes advanced (ahead).
-// trials[0]..trials[retval-1] contain the steps to encode.
+// trials[0]..trials[ahead-1] contain the steps to encode.
 // ( trials[0].dis == -1 && trials[0].price == 1 ) means literal.
 //
 int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances],
@@ -690,7 +690,7 @@ bool LZ_encoder::encode_member( const unsigned long long member_size )
     const uint8_t cur_byte = matchfinder[0];
     renc.encode_bit( bm_match[state()][0], 0 );
     encode_literal( prev_byte, cur_byte );
-    crc32.update( crc_, cur_byte );
+    crc32.update_byte( crc_, cur_byte );
     matchfinder.get_match_pairs();
     matchfinder.move_pos();
     }
@@ -720,7 +720,7 @@ bool LZ_encoder::encode_member( const unsigned long long member_size )
         {
         const uint8_t prev_byte = matchfinder[-ahead-1];
         const uint8_t cur_byte = matchfinder[-ahead];
-        crc32.update( crc_, cur_byte );
+        crc32.update_byte( crc_, cur_byte );
         if( state.is_char() )
           encode_literal( prev_byte, cur_byte );
         else
@@ -732,7 +732,7 @@ bool LZ_encoder::encode_member( const unsigned long long member_size )
         }
       else					// match or repeated match
         {
-        crc32.update( crc_, matchfinder.ptr_to_current_pos() - ahead, len );
+        crc32.update_buf( crc_, matchfinder.ptr_to_current_pos() - ahead, len );
         mtf_reps( dis, rep_distances );
         bit = ( dis < num_rep_distances );
         renc.encode_bit( bm_rep[state()], bit );
diff --git a/encoder.h b/encoder.h
index 973ba6c..577ceeb 100644
--- a/encoder.h
+++ b/encoder.h
@@ -42,7 +42,7 @@ public:
 
 extern Dis_slots dis_slots;
 
-static inline uint8_t get_slot( const uint32_t dis )
+inline uint8_t get_slot( const uint32_t dis )
   {
   if( dis < (1 << 10) ) return dis_slots[dis];
   if( dis < (1 << 19) ) return dis_slots[dis>> 9] + 18;
diff --git a/fast_encoder.cc b/fast_encoder.cc
index 21e1a2b..dfbb429 100644
--- a/fast_encoder.cc
+++ b/fast_encoder.cc
@@ -133,7 +133,7 @@ bool FLZ_encoder::encode_member( const unsigned long long member_size )
     const uint8_t cur_byte = fmatchfinder[0];
     renc.encode_bit( bm_match[state()][0], 0 );
     encode_literal( prev_byte, cur_byte );
-    crc32.update( crc_, cur_byte );
+    crc32.update_byte( crc_, cur_byte );
     fmatchfinder.longest_match_len( 1 );
     }
 
@@ -153,7 +153,7 @@ bool FLZ_encoder::encode_member( const unsigned long long member_size )
       }
     if( len > min_match_len && len + 4 > main_len )
       {
-      crc32.update( crc_, fmatchfinder.ptr_to_current_pos(), len );
+      crc32.update_buf( crc_, fmatchfinder.ptr_to_current_pos(), len );
       renc.encode_bit( bm_match[state()][pos_state], 1 );
       renc.encode_bit( bm_rep[state()], 1 );
       const bool bit = ( dis == 0 );
@@ -178,7 +178,7 @@ bool FLZ_encoder::encode_member( const unsigned long long member_size )
     if( main_len > min_match_len ||
         ( main_len == min_match_len && match_distance < modeled_distances ) )
       {
-      crc32.update( crc_, fmatchfinder.ptr_to_current_pos(), main_len );
+      crc32.update_buf( crc_, fmatchfinder.ptr_to_current_pos(), main_len );
       dis = match_distance;
       renc.encode_bit( bm_match[state()][pos_state], 1 );
       renc.encode_bit( bm_rep[state()], 0 );
@@ -193,7 +193,7 @@ bool FLZ_encoder::encode_member( const unsigned long long member_size )
     const uint8_t prev_byte = fmatchfinder[-1];
     const uint8_t cur_byte = fmatchfinder[0];
     const uint8_t match_byte = fmatchfinder[-reps[0]-1];
-    crc32.update( crc_, cur_byte );
+    crc32.update_byte( crc_, cur_byte );
     fmatchfinder.move_pos();
 
     if( match_byte == cur_byte )
diff --git a/lzip.h b/lzip.h
index 20912cf..b563833 100644
--- a/lzip.h
+++ b/lzip.h
@@ -30,10 +30,11 @@ public:
     static const int next[states] = { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 };
     st = next[st];
     }
-
-  void set_match()     { st = ( ( st < 7 ) ? 7 : 10 ); }
-  void set_rep()       { st = ( ( st < 7 ) ? 8 : 11 ); }
-  void set_short_rep() { st = ( ( st < 7 ) ? 9 : 11 ); }
+  void set_char1()     { st -= ( st < 4 ) ? st : 3; }	// for st < 7
+  void set_char2()     { st -= ( st < 10 ) ? 3 : 6; }	// for st >= 7
+  void set_match()     { st = ( st < 7 ) ? 7 : 10; }
+  void set_rep()       { st = ( st < 7 ) ? 8 : 11; }
+  void set_short_rep() { st = ( st < 7 ) ? 9 : 11; }
   };
 
 
@@ -147,10 +148,11 @@ public:
 
   uint32_t operator[]( const uint8_t byte ) const { return data[byte]; }
 
-  void update( uint32_t & crc, const uint8_t byte ) const
+  void update_byte( uint32_t & crc, const uint8_t byte ) const
     { crc = data[(crc^byte)&0xFF] ^ ( crc >> 8 ); }
 
-  void update( uint32_t & crc, const uint8_t * const buffer, const int size ) const
+  void update_buf( uint32_t & crc, const uint8_t * const buffer,
+                   const int size ) const
     {
     for( int i = 0; i < size; ++i )
       crc = data[(crc^buffer[i])&0xFF] ^ ( crc >> 8 );
@@ -192,15 +194,15 @@ struct File_header
     return sz;
     }
 
-  bool dictionary_size( const int sz )
+  bool dictionary_size( const unsigned sz )
     {
     if( sz >= min_dictionary_size && sz <= max_dictionary_size )
       {
       data[5] = real_bits( sz - 1 );
       if( sz > min_dictionary_size )
         {
-        const int base_size = 1 << data[5];
-        const int wedge = base_size / 16;
+        const unsigned base_size = 1 << data[5];
+        const unsigned wedge = base_size / 16;
         for( int i = 7; i >= 1; --i )
           if( base_size - ( i * wedge ) >= sz )
             { data[5] |= ( i << 5 ); break; }
diff --git a/main.cc b/main.cc
index 921684a..bd5c8c9 100644
--- a/main.cc
+++ b/main.cc
@@ -89,8 +89,6 @@ struct Lzma_options
   };
 
 enum Mode { m_compress, m_decompress, m_test };
-const unsigned long long max_member_size = 0x1000000000000000ULL;
-const unsigned long long max_volume_size = 0x7FFFFFFFFFFFFFFFULL;
 
 std::string output_filename;
 int outfd = -1;
@@ -130,7 +128,8 @@ void show_help()
                "The bidimensional parameter space of LZMA can't be mapped to a linear\n"
                "scale optimal for all files. If your files are large, very repetitive,\n"
                "etc, you may need to use the --match-length and --dictionary-size\n"
-               "options directly to achieve optimal performance.\n"
+               "options directly to achieve optimal performance. For example, -9m64\n"
+               "usually compresses executables more (and faster) than -9.\n"
                "\nExit status: 0 for a normal exit, 1 for environmental problems (file\n"
                "not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or\n"
                "invalid input file, 3 for an internal consistency error (eg, bug) which\n"
@@ -163,7 +162,7 @@ void show_header( const File_header & header )
   for( int i = 0; i < 8 && ( num > 9999 || ( exact && num >= factor ) ); ++i )
     { num /= factor; if( num % factor != 0 ) exact = false;
       p = prefix[i]; np = ""; }
-  if( verbosity >= 4 )
+  if( verbosity >= 4 && header.version() != 1 )
     std::fprintf( stderr, "version %d, ", header.version() );
   std::fprintf( stderr, "dictionary size %s%4u %sB.  ", np, num, p );
   }
@@ -275,12 +274,13 @@ int open_instream( const char * const name, struct stat * const in_statsp,
       const bool can_read = ( i == 0 &&
                               ( S_ISBLK( mode ) || S_ISCHR( mode ) ||
                                 S_ISFIFO( mode ) || S_ISSOCK( mode ) ) );
-      if( i != 0 || ( !S_ISREG( mode ) && ( !to_stdout || !can_read ) ) )
+      const bool no_ofile = to_stdout || program_mode == m_test;
+      if( i != 0 || ( !S_ISREG( mode ) && ( !can_read || !no_ofile ) ) )
         {
         if( verbosity >= 0 )
           std::fprintf( stderr, "%s: Input file '%s' is not a regular file%s.\n",
                         program_name, name,
-                        ( can_read && !to_stdout ) ?
+                        ( can_read && !no_ofile ) ?
                         " and '--stdout' was not specified" : "" );
         close( infd );
         infd = -1;
@@ -602,7 +602,7 @@ int decompress( const int infd, const Pretty_print & pp, const bool testing )
       if( rdec.finished() )			// End Of File
         {
         if( first_member )
-          { pp( "Error reading member header" ); retval = 1; }
+          { pp( "File ends unexpectedly at member header" ); retval = 2; }
         else if( verbosity >= 4 && size > 0 )
           show_trailing_garbage( header.data, size, pp, true );
         break;
@@ -754,6 +754,8 @@ int main( const int argc, const char * const argv[] )
     { 3 << 23, 132 },		// -8
     { 1 << 25, 273 } };		// -9
   Lzma_options encoder_options = option_mapping[6];	// default = "-6"
+  const unsigned long long max_member_size = 0x0100000000000000ULL;
+  const unsigned long long max_volume_size = 0x4000000000000000ULL;
   unsigned long long member_size = max_member_size;
   unsigned long long volume_size = 0;
   std::string input_filename;
diff --git a/testsuite/check.sh b/testsuite/check.sh
index 8adf23b..8d6bb79 100755
--- a/testsuite/check.sh
+++ b/testsuite/check.sh
@@ -1,5 +1,5 @@
 #! /bin/sh
-# check script for Lzip - Data compressor based on the LZMA algorithm
+# check script for Lzip - LZMA lossless data compressor
 # Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
 #
 # This script is free software: you have unlimited permission
@@ -35,6 +35,18 @@ if [ $? = 1 ] ; then printf . ; else fail=1 ; printf - ; fi
 if [ $? = 1 ] ; then printf . ; else fail=1 ; printf - ; fi
 "${LZIP}" -cqm274 in > /dev/null
 if [ $? = 1 ] ; then printf . ; else fail=1 ; printf - ; fi
+"${LZIP}" -tq in
+if [ $? = 2 ] ; then printf . ; else fail=1 ; printf - ; fi
+"${LZIP}" -tq < in
+if [ $? = 2 ] ; then printf . ; else fail=1 ; printf - ; fi
+"${LZIP}" -cdq in
+if [ $? = 2 ] ; then printf . ; else fail=1 ; printf - ; fi
+"${LZIP}" -cdq < in
+if [ $? = 2 ] ; then printf . ; else fail=1 ; printf - ; fi
+dd if="${in_lz}" bs=1 count=6 2> /dev/null | "${LZIP}" -tq
+if [ $? = 2 ] ; then printf . ; else printf - ; fail=1 ; fi
+dd if="${in_lz}" bs=1 count=20 2> /dev/null | "${LZIP}" -tq
+if [ $? = 2 ] ; then printf . ; else printf - ; fail=1 ; fi
 
 "${LZIP}" -t "${in_lz}" || fail=1
 "${LZIP}" -cd "${in_lz}" > copy || fail=1