Merging upstream version 1.10.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

24 files changed, 813 insertions, 456 deletions

diff --git a/ChangeLog b/ChangeLog
index 88b6ab2..827259c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
+2018-02-06  Antonio Diaz Diaz  <antonio@gnu.org>
+
+	* Version 1.10 released.
+	* main.c: Added new option '--loose-trailing'.
+	* Improved corrupt header detection to HD=3.
+	* main.c: Show corrupt or truncated header in multimember file.
+	* main.c (main): Option '-S, --volume-size' now keeps input files.
+	* encoder_base.*: Adjust dictionary size for each member.
+	* Replaced 'bits/byte' with inverse compression ratio in output.
+	* Show progress of decompression at verbosity level 2 (-vv).
+	* Show progress of (de)compression only if stderr is a terminal.
+	* main.c: Show final diagnostic when testing multiple files.
+	* main.c: Do not add a second .lz extension to the arg of -o.
+	* decoder.c (LZd_verify_trailer): Show stored sizes also in hex.
+	  Show dictionary size at verbosity level 4 (-vvvv).
+	* lzip.texi: Added chapter 'Output'.
+
 2017-04-13  Antonio Diaz Diaz  <antonio@gnu.org>
 
 	* Version 1.9 released.
@@ -24,8 +41,8 @@
 	* clzip.texi: Added chapter 'Trailing data'.
 	* configure: Avoid warning on some shells when testing for gcc.
 	* Makefile.in: Detect the existence of install-info.
-	* testsuite/check.sh: A POSIX shell is required to run the tests.
-	* testsuite/check.sh: Don't check error messages.
+	* check.sh: A POSIX shell is required to run the tests.
+	* check.sh: Don't check error messages.
 
 2015-07-07  Antonio Diaz Diaz  <antonio@gnu.org>
 
@@ -108,7 +125,7 @@
 	* Translated to C from the C++ source of lzip 1.10.
 
 
-Copyright (C) 2010-2017 Antonio Diaz Diaz.
+Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
 This file is a collection of facts, and thus it is not copyrightable,
 but just in case, you have unlimited permission to copy, distribute and
diff --git a/INSTALL b/INSTALL
index 0808525..e64dead 100644
--- a/INSTALL
+++ b/INSTALL
@@ -62,7 +62,7 @@ After running 'configure', you can run 'make' and 'make install' as
 explained above.
 
 
-Copyright (C) 2010-2017 Antonio Diaz Diaz.
+Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
 This file is free documentation: you have unlimited permission to copy,
 distribute and modify it.
diff --git a/NEWS b/NEWS
index 1f85396..2a84711 100644
--- a/NEWS
+++ b/NEWS
@@ -1,21 +1,42 @@
-Changes in version 1.9:
+Changes in version 1.10:
 
-The option '-l, --list' has been ported from lziprecover.
+The option '--loose-trailing', has been added.
 
-It is now an error to specify two or more different operations in the
-command line (--decompress, --list or --test).
+The test used by clzip to discriminate trailing data from a corrupt
+header in multimember or concatenated files has been improved to a
+Hamming distance (HD) of 3, and the 3 bit flips must happen in different
+magic bytes for the test to fail. As a consequence some kinds of files
+no longer can be appended to a lzip file as trailing data unless the
+'--loose-trailing' option is used when decompressing.
+Lziprecover can be used to remove conflicting trailing data from a file.
 
-Compression time of option '-0' has been reduced by 6%.
+The contents of a corrupt or truncated header found in a multimember
+file is now shown, after the error message, in the same format as
+trailing data.
 
-Compression time of options '-1' to '-9' has been reduced by 1%.
+Option '-S, --volume-size' now keeps input files unchanged.
 
-Decompression time has been reduced by 7%.
+When creating multimember files or splitting the output in volumes, the
+dictionary size is now adjusted for each member individually.
 
-In test mode, clzip now continues checking the rest of the files if any
-input file is a terminal.
+The 'bits/byte' ratio has been replaced with the inverse compression
+ratio in the output.
 
-Trailing data are now shown both in hexadecimal and as a string of
-printable ASCII characters.
+The progress of decompression is now shown at verbosity level 2 (-vv) or
+higher.
 
-Three missing chapters have been added to the manual, which now contains
-all the chapters of the lzip manual.
+Progress of (de)compression is only shown if stderr is a terminal.
+
+A final diagnostic is now shown at verbosity level 1 (-v) or higher if
+any file fails the test when testing multiple files.
+
+A second '.lz' extension is no longer added to the argument of '-o' if
+it already ends in '.lz' or '.tlz'.
+
+In case of (de)compressed size mismatch, the stored size is now also
+shown in hexadecimal to ease visual comparison.
+
+The dictionary size is now shown at verbosity level 4 (-vvvv) when
+decompressing or testing.
+
+The new chapter "Meaning of clzip's output" has been added to the manual.
diff --git a/README b/README
index cc5fd73..bf8e47d 100644
--- a/README
+++ b/README
@@ -78,7 +78,7 @@ incomprehensible and therefore pointless.
 
 Clzip will correctly decompress a file which is the concatenation of two
 or more compressed files. The result is the concatenation of the
-corresponding uncompressed files. Integrity testing of concatenated
+corresponding decompressed files. Integrity testing of concatenated
 compressed files is also supported.
 
 Clzip can produce multimember files, and lziprecover can safely recover
@@ -116,7 +116,7 @@ range encoding), Igor Pavlov (for putting all the above together in
 LZMA), and Julian Seward (for bzip2's CLI).
 
 
-Copyright (C) 2010-2017 Antonio Diaz Diaz.
+Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
 This file is free documentation: you have unlimited permission to copy,
 distribute and modify it.
diff --git a/carg_parser.c b/carg_parser.c
index 6850643..10ad4dc 100644
--- a/carg_parser.c
+++ b/carg_parser.c
@@ -1,5 +1,5 @@
 /*  Arg_parser - POSIX/GNU command line argument parser. (C version)
-    Copyright (C) 2006-2017 Antonio Diaz Diaz.
+    Copyright (C) 2006-2018 Antonio Diaz Diaz.
 
     This library is free software. Redistribution and use in source and
     binary forms, with or without modification, are permitted provided
diff --git a/carg_parser.h b/carg_parser.h
index c4ce31d..e1c70dd 100644
--- a/carg_parser.h
+++ b/carg_parser.h
@@ -1,5 +1,5 @@
 /*  Arg_parser - POSIX/GNU command line argument parser. (C version)
-    Copyright (C) 2006-2017 Antonio Diaz Diaz.
+    Copyright (C) 2006-2018 Antonio Diaz Diaz.
 
     This library is free software. Redistribution and use in source and
     binary forms, with or without modification, are permitted provided
diff --git a/configure b/configure
index 5ef6211..c86587b 100755
--- a/configure
+++ b/configure
@@ -1,12 +1,12 @@
 #! /bin/sh
 # configure script for Clzip - LZMA lossless data compressor
-# Copyright (C) 2010-2017 Antonio Diaz Diaz.
+# Copyright (C) 2010-2018 Antonio Diaz Diaz.
 #
 # This configure script is free software: you have unlimited permission
 # to copy, distribute and modify it.
 
 pkgname=clzip
-pkgversion=1.9
+pkgversion=1.10
 progname=clzip
 srctrigger=doc/${pkgname}.texi
 
@@ -168,7 +168,7 @@ echo "LDFLAGS = ${LDFLAGS}"
 rm -f Makefile
 cat > Makefile << EOF
 # Makefile for Clzip - LZMA lossless data compressor
-# Copyright (C) 2010-2017 Antonio Diaz Diaz.
+# Copyright (C) 2010-2018 Antonio Diaz Diaz.
 # This file was generated automatically by configure. Don't edit.
 #
 # This Makefile is free software: you have unlimited permission
diff --git a/decoder.c b/decoder.c
index 453d271..e809df6 100644
--- a/decoder.c
+++ b/decoder.c
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -29,24 +29,6 @@
 #include "decoder.h"
 
 
-void Pp_show_msg( struct Pretty_print * const pp, const char * const msg )
-  {
-  if( verbosity >= 0 )
-    {
-    if( pp->first_post )
-      {
-      unsigned i;
-      pp->first_post = false;
-      fprintf( stderr, "  %s: ", pp->name );
-      for( i = strlen( pp->name ); i < pp->longest_name; ++i )
-        fputc( ' ', stderr );
-      if( !msg ) fflush( stderr );
-      }
-    if( msg ) fprintf( stderr, "%s\n", msg );
-    }
-  }
-
-
 /* Returns the number of bytes really read.
    If (returned value < size) and (errno == 0), means EOF was reached.
 */
@@ -94,6 +76,7 @@ bool Rd_read_block( struct Range_decoder * const rdec )
     rdec->at_stream_end = ( rdec->stream_pos < rd_buffer_size );
     rdec->partial_member_pos += rdec->pos;
     rdec->pos = 0;
+    show_dprogress( 0, 0, 0, 0 );
     }
   return rdec->pos < rdec->stream_pos;
   }
@@ -122,6 +105,8 @@ static bool LZd_verify_trailer( struct LZ_decoder * const d,
   int size = Rd_read_data( d->rdec, trailer, Ft_size );
   const unsigned long long data_size = LZd_data_position( d );
   const unsigned long long member_size = Rd_member_position( d->rdec );
+  unsigned td_crc;
+  unsigned long long td_size, tm_size;
   bool error = false;
 
   if( size < Ft_size )
@@ -136,45 +121,56 @@ static bool LZd_verify_trailer( struct LZ_decoder * const d,
     while( size < Ft_size ) trailer[size++] = 0;
     }
 
-  if( Ft_get_data_crc( trailer ) != LZd_crc( d ) )
+  td_crc = Ft_get_data_crc( trailer );
+  if( td_crc != LZd_crc( d ) )
     {
     error = true;
     if( verbosity >= 0 )
       {
       Pp_show_msg( pp, 0 );
-      fprintf( stderr, "CRC mismatch; trailer says %08X, data CRC is %08X\n",
-               Ft_get_data_crc( trailer ), LZd_crc( d ) );
+      fprintf( stderr, "CRC mismatch; stored %08X, computed %08X\n",
+               td_crc, LZd_crc( d ) );
       }
     }
-  if( Ft_get_data_size( trailer ) != data_size )
+  td_size = Ft_get_data_size( trailer );
+  if( td_size != data_size )
     {
     error = true;
     if( verbosity >= 0 )
       {
       Pp_show_msg( pp, 0 );
-      fprintf( stderr, "Data size mismatch; trailer says %llu, data size is %llu (0x%llX)\n",
-               Ft_get_data_size( trailer ), data_size, data_size );
+      fprintf( stderr, "Data size mismatch; stored %llu (0x%llX), computed %llu (0x%llX)\n",
+               td_size, td_size, data_size, data_size );
       }
     }
-  if( Ft_get_member_size( trailer ) != member_size )
+  tm_size = Ft_get_member_size( trailer );
+  if( tm_size != member_size )
     {
     error = true;
     if( verbosity >= 0 )
       {
       Pp_show_msg( pp, 0 );
-      fprintf( stderr, "Member size mismatch; trailer says %llu, member size is %llu (0x%llX)\n",
-               Ft_get_member_size( trailer ), member_size, member_size );
+      fprintf( stderr, "Member size mismatch; stored %llu (0x%llX), computed %llu (0x%llX)\n",
+               tm_size, tm_size, member_size, member_size );
       }
     }
-  if( !error && verbosity >= 2 && data_size > 0 && member_size > 0 )
-    fprintf( stderr, "%6.3f:1, %6.3f bits/byte, %5.2f%% saved.  ",
-             (double)data_size / member_size,
-             ( 8.0 * member_size ) / data_size,
-             100.0 * ( 1.0 - ( (double)member_size / data_size ) ) );
-  if( !error && verbosity >= 4 )
-    fprintf( stderr, "CRC %08X, decompressed %9llu, compressed %8llu.  ",
-             LZd_crc( d ), data_size, member_size );
-  return !error;
+  if( error ) return false;
+  if( verbosity >= 2 )
+    {
+    if( verbosity >= 4 ) show_header( d->dictionary_size );
+    if( data_size == 0 || member_size == 0 )
+      fputs( "no data compressed.  ", stderr );
+    else
+      fprintf( stderr, "%6.3f:1, %5.2f%% ratio, %5.2f%% saved.  ",
+               (double)data_size / member_size,
+               ( 100.0 * member_size ) / data_size,
+               100.0 - ( ( 100.0 * member_size ) / data_size ) );
+    if( verbosity >= 4 ) fprintf( stderr, "CRC %08X, ", td_crc );
+    if( verbosity >= 3 )
+      fprintf( stderr, "decompressed %9llu, compressed %8llu.  ",
+               data_size, member_size );
+    }
+  return true;
   }
 
 
diff --git a/decoder.h b/decoder.h
index 2f96575..11ba869 100644
--- a/decoder.h
+++ b/decoder.h
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -239,11 +239,7 @@ struct LZ_decoder
 void LZd_flush_data( struct LZ_decoder * const d );
 
 static inline uint8_t LZd_peek_prev( const struct LZ_decoder * const d )
-  {
-  if( d->pos > 0 ) return d->buffer[d->pos-1];
-  if( d->pos_wrapped ) return d->buffer[d->dictionary_size-1];
-  return 0;			/* prev_byte of first byte */
-  }
+  { return d->buffer[((d->pos > 0) ? d->pos : d->dictionary_size)-1]; }
 
 static inline uint8_t LZd_peek( const struct LZ_decoder * const d,
                                 const unsigned distance )
@@ -305,6 +301,8 @@ static inline bool LZd_init( struct LZ_decoder * const d,
   d->crc = 0xFFFFFFFFU;
   d->outfd = ofd;
   d->pos_wrapped = false;
+  /* prev_byte of first byte; also for LZd_peek( 0 ) on corrupt file */
+  d->buffer[d->dictionary_size-1] = 0;
   return true;
   }
 
diff --git a/doc/clzip.1 b/doc/clzip.1
index 8522ad0..e7cbaec 100644
--- a/doc/clzip.1
+++ b/doc/clzip.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH CLZIP "1" "April 2017" "clzip 1.9" "User Commands"
+.TH CLZIP "1" "February 2018" "clzip 1.10" "User Commands"
 .SH NAME
 clzip \- reduces the size of files
 .SH SYNOPSIS
@@ -52,7 +52,7 @@ suppress all messages
 set dictionary size limit in bytes [8 MiB]
 .TP
 \fB\-S\fR, \fB\-\-volume\-size=\fR<bytes>
-set volume size limit in bytes
+set volume size limit in bytes, implies \fB\-k\fR
 .TP
 \fB\-t\fR, \fB\-\-test\fR
 test compressed file integrity
@@ -68,6 +68,9 @@ alias for \fB\-0\fR
 .TP
 \fB\-\-best\fR
 alias for \fB\-9\fR
+.TP
+\fB\-\-loose\-trailing\fR
+allow trailing data seeming corrupt header
 .PP
 If no file names are given, or if a file is '\-', clzip compresses or
 decompresses from standard input to standard output.
@@ -90,7 +93,7 @@ Report bugs to lzip\-bug@nongnu.org
 .br
 Clzip home page: http://www.nongnu.org/lzip/clzip.html
 .SH COPYRIGHT
-Copyright \(co 2017 Antonio Diaz Diaz.
+Copyright \(co 2018 Antonio Diaz Diaz.
 License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
diff --git a/doc/clzip.info b/doc/clzip.info
index f6e483f..1fddbd8 100644
--- a/doc/clzip.info
+++ b/doc/clzip.info
@@ -11,11 +11,12 @@ File: clzip.info,  Node: Top,  Next: Introduction,  Up: (dir)
 Clzip Manual
 ************
 
-This manual is for Clzip (version 1.9, 13 April 2017).
+This manual is for Clzip (version 1.10, 6 February 2018).
 
 * Menu:
 
 * Introduction::           Purpose and features of clzip
+* Output::                 Meaning of clzip's output
 * Invoking clzip::         Command line interface
 * Quality assurance::      Design, development and testing of lzip
 * File format::            Detailed format of the compressed file
@@ -28,13 +29,13 @@ This manual is for Clzip (version 1.9, 13 April 2017).
 * Concept index::          Index of concepts
 
 
-   Copyright (C) 2010-2017 Antonio Diaz Diaz.
+   Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
    This manual is free documentation: you have unlimited permission to
 copy, distribute and modify it.
 
 
-File: clzip.info,  Node: Introduction,  Next: Invoking clzip,  Prev: Top,  Up: Top
+File: clzip.info,  Node: Introduction,  Next: Output,  Prev: Top,  Up: Top
 
 1 Introduction
 **************
@@ -55,7 +56,7 @@ archiving, taking into account both data integrity and decoder
 availability:
 
    * The lzip format provides very safe integrity checking and some data
-     recovery means. The lziprecover program can repair bit-flip errors
+     recovery means. The lziprecover program can repair bit flip errors
      (one of the most common forms of data corruption) in lzip files,
      and provides data recovery capabilities, including error-checked
      merging of damaged copies of a file.  *Note Data safety:
@@ -129,7 +130,7 @@ entirely incomprehensible and therefore pointless.
 
    Clzip will correctly decompress a file which is the concatenation of
 two or more compressed files. The result is the concatenation of the
-corresponding uncompressed files. Integrity testing of concatenated
+corresponding decompressed files. Integrity testing of concatenated
 compressed files is also supported.
 
    Clzip can produce multimember files, and lziprecover can safely
@@ -142,14 +143,58 @@ multivolume compressed tar archives.
 automatically creating multimember output. The members so created are
 large, about 2 PiB each.
 
+
+File: clzip.info,  Node: Output,  Next: Invoking clzip,  Prev: Introduction,  Up: Top
+
+2 Meaning of clzip's output
+***************************
+
+The output of clzip looks like this:
+
+     clzip -v foo
+       foo:  6.676:1, 14.98% ratio, 85.02% saved, 450560 in, 67493 out.
+
+     clzip -tvv foo.lz
+       foo.lz:  6.676:1, 14.98% ratio, 85.02% saved.  ok
+
+   The meaning of each field is as follows:
+
+'N:1'
+     The compression ratio (uncompressed_size / compressed_size), shown
+     as N to 1.
+
+'ratio'
+     The inverse compression ratio
+     (compressed_size / uncompressed_size), shown as a percentage. A
+     decimal ratio is easily obtained by moving the decimal point two
+     places to the left; 14.98% = 0.1498.
+
+'saved'
+     The space saved by compression (1 - ratio), shown as a percentage.
+
+'in'
+     The size of the uncompressed data. When decompressing or testing,
+     it is shown as 'decompressed'. Note that clzip always prints the
+     uncompressed size before the compressed size when compressing,
+     decompressing, testing or listing.
+
+'out'
+     The size of the compressed data. When decompressing or testing, it
+     is shown as 'compressed'.
+
+
+   When decompressing or testing at verbosity level 4 (-vvvv), the
+dictionary size used to compress the file and the CRC32 of the
+uncompressed data are also shown.
+
    LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may
 never have been compressed. Decompressed is used to refer to data which
 have undergone the process of decompression.
 
 
-File: clzip.info,  Node: Invoking clzip,  Next: Quality assurance,  Prev: Introduction,  Up: Top
+File: clzip.info,  Node: Invoking clzip,  Next: Quality assurance,  Prev: Output,  Up: Top
 
-2 Invoking clzip
+3 Invoking clzip
 ****************
 
 The format for running clzip is:
@@ -160,7 +205,7 @@ The format for running clzip is:
 other FILES and is read just once, the first time it appears in the
 command line.
 
-   Clzip supports the following options:
+   clzip supports the following options:
 
 '-h'
 '--help'
@@ -179,9 +224,10 @@ command line.
 
 '-b BYTES'
 '--member-size=BYTES'
-     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 2 PiB. Defaults to 2 PiB.
+     When compressing, 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 2 PiB. Defaults to
+     2 PiB.
 
 '-c'
 '--stdout'
@@ -189,15 +235,15 @@ command line.
      unchanged.  If compressing several files, each file is compressed
      independently.  This option is needed when reading from a named
      pipe (fifo) or from a device. Use it also to recover as much of
-     the uncompressed data as possible when decompressing a corrupt
+     the decompressed data as possible when decompressing a corrupt
      file.
 
 '-d'
 '--decompress'
-     Decompress the specified file(s). If a file does not exist or
-     can't be opened, clzip continues decompressing the rest of the
-     files. If a file fails to decompress, clzip exits immediately
-     without decompressing the rest of the files.
+     Decompress the specified files. If a file does not exist or can't
+     be opened, clzip continues decompressing the rest of the files. If
+     a file fails to decompress, or is a terminal, clzip exits
+     immediately without decompressing the rest of the files.
 
 '-f'
 '--force'
@@ -205,8 +251,8 @@ command line.
 
 '-F'
 '--recompress'
-     Force re-compression of files whose name already has the '.lz' or
-     '.tlz' suffix.
+     When compressing, force re-compression of files whose name already
+     has the '.lz' or '.tlz' suffix.
 
 '-k'
 '--keep'
@@ -216,7 +262,7 @@ command line.
 '-l'
 '--list'
      Print the uncompressed size, compressed size and percentage saved
-     of the specified file(s). Trailing data are ignored. The values
+     of the specified files. Trailing data are ignored. The values
      produced are correct even for multimember files. If more than one
      file is given, a final line containing the cumulative sizes is
      printed. With '-v', the dictionary size, the number of members in
@@ -230,19 +276,20 @@ command line.
 
 '-m BYTES'
 '--match-length=BYTES'
-     Set the match length limit in bytes. After a match this long is
-     found, the search is finished. Valid values range from 5 to 273.
-     Larger values usually give better compression ratios but longer
-     compression times.
+     When compressing, set the match length limit in bytes. After a
+     match this long is found, the search is finished. Valid values
+     range from 5 to 273. Larger values usually give better compression
+     ratios but longer compression times.
 
 '-o FILE'
 '--output=FILE'
      When reading from standard input and '--stdout' has not been
      specified, use 'FILE' as the virtual name of the uncompressed
-     file. This produces a file named 'FILE' when decompressing, a file
-     named 'FILE.lz' when compressing, and several files named
-     'FILE00001.lz', 'FILE00002.lz', etc, when compressing and
-     splitting the output in volumes.
+     file. This produces a file named 'FILE' when decompressing, or a
+     file named 'FILE.lz' when compressing. A second '.lz' extension is
+     not added if 'FILE' already ends in '.lz' or '.tlz'. When
+     compressing and splitting the output in volumes, several files
+     named 'FILE00001.lz', 'FILE00002.lz', etc, are created.
 
 '-q'
 '--quiet'
@@ -250,13 +297,13 @@ command line.
 
 '-s BYTES'
 '--dictionary-size=BYTES'
-     Set the dictionary size limit in bytes. Clzip will use the smallest
-     possible dictionary size for each file without exceeding this
-     limit.  Valid values range from 4 KiB to 512 MiB. Values 12 to 29
-     are interpreted as powers of two, meaning 2^12 to 2^29 bytes. 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 (BYTES / 8) to it.
+     When compressing, set the dictionary size limit in bytes. Clzip
+     will use the smallest possible dictionary size for each file
+     without exceeding this limit. Valid values range from 4 KiB to
+     512 MiB. Values 12 to 29 are interpreted as powers of two, meaning
+     2^12 to 2^29 bytes. 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 (BYTES / 8) to it.
 
      For maximum compression you should use a dictionary size limit as
      large as possible, but keep in mind that the decompression memory
@@ -265,38 +312,40 @@ command line.
 
 '-S BYTES'
 '--volume-size=BYTES'
-     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
-     multimember, 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.
+     When compressing, 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. Input files are kept
+     unchanged. Each volume is a complete, maybe multimember, 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'
-     Check integrity of the specified file(s), but don't decompress
-     them.  This really performs a trial decompression and throws away
-     the result.  Use it together with '-v' to see information about
-     the file(s). If a file fails the test, does not exist, can't be
-     opened, or is a terminal, clzip continues checking the rest of the
-     files.
+     Check integrity of the specified files, but don't decompress them.
+     This really performs a trial decompression and throws away the
+     result. Use it together with '-v' to see information about the
+     files. If a file fails the test, does not exist, can't be opened,
+     or is a terminal, clzip continues checking the rest of the files.
+     A final diagnostic is shown at verbosity level 1 or higher if any
+     file fails the test when testing multiple files.
 
 '-v'
 '--verbose'
      Verbose mode.
-     When compressing, show the compression ratio for each file
-     processed. A second '-v' shows the progress of compression.
+     When compressing, show the compression ratio and size for each file
+     processed.
      When decompressing or testing, further -v's (up to 4) increase the
      verbosity level, showing status, compression ratio, dictionary
      size, trailer contents (CRC, data size, member size), and up to 6
      bytes of trailing data (if any) both in hexadecimal and as a
      string of printable ASCII characters.
+     Two or more '-v' options show the progress of (de)compression.
 
 '-0 .. -9'
      Set the compression parameters (dictionary size and match length
      limit) as shown in the table below. The default compression level
      is '-6'.  Note that '-9' can be much slower than '-0'. These
-     options have no effect when decompressing.
+     options have no effect when decompressing, testing or listing.
 
      The bidimensional parameter space of LZMA can't be mapped to a
      linear scale optimal for all files. If your files are large, very
@@ -319,6 +368,13 @@ command line.
 '--best'
      Aliases for GNU gzip compatibility.
 
+'--loose-trailing'
+     When decompressing, testing or listing, allow trailing data whose
+     first bytes are so similar to the magic bytes of a lzip header
+     that they can be confused with a corrupt header. Use this option
+     if a file triggers a "corrupt header" error and the cause is not
+     indeed a corrupt header.
+
 
    Numbers given as arguments to options may be followed by a multiplier
 and an optional 'B' for "byte".
@@ -344,7 +400,7 @@ caused clzip to panic.
 
 File: clzip.info,  Node: Quality assurance,  Next: File format,  Prev: Invoking clzip,  Up: Top
 
-3 Design, development and testing of lzip
+4 Design, development and testing of lzip
 *****************************************
 
 There are two ways of constructing a software design: One way is to make
@@ -359,7 +415,7 @@ describes the lessons learned from previous compressors (gzip and
 bzip2), and their application to the design of lzip.
 
 
-3.1 Format design
+4.1 Format design
 =================
 
 When gzip was designed in 1992, computers and operating systems were
@@ -377,7 +433,7 @@ one of gzip.
 
    Probably the worst defect of the gzip format from the point of view
 of data safety is the variable size of its header. If the byte at
-offset 3 (flags) of a gzip member gets corrupted, it may become very
+offset 3 (flags) of a gzip member gets corrupted, it may become
 difficult to recover the data, even if the compressed blocks are
 intact, because it can't be known with certainty where the compressed
 blocks begin.
@@ -399,8 +455,8 @@ error detection. Any distance larger than the dictionary size acts as a
 forbidden symbol, allowing the decompressor to detect the approximate
 position of errors, and leaving very little work for the check sequence
 (CRC and data sizes) in the detection of errors. Lzip is usually able
-to detect all posible bit-flips in the compressed data without
-resorting to the check sequence. It would be very difficult to write an
+to detect all posible bit flips in the compressed data without
+resorting to the check sequence. It would be difficult to write an
 automatic recovery tool like lziprecover for the gzip format. And, as
 far as I know, it has never been written.
 
@@ -409,15 +465,14 @@ decompressed data because it provides more accurate error detection than
 CRC64 up to a compressed size of about 16 GiB, a size larger than that
 of most files. In the case of lzip, the additional detection capability
 of the decompressor reduces the probability of undetected errors more
-than a million times, making CRC32 more accurate than CRC64 up to about
-20 PiB of compressed size.
+than a million times beyond what the CRC32 alone provides.
 
    The lzip format is designed for long-term archiving. Therefore it
 excludes any unneeded features that may interfere with the future
-extraction of the uncompressed data.
+extraction of the decompressed data.
 
 
-3.1.1 Gzip format (mis)features not present in lzip
+4.1.1 Gzip format (mis)features not present in lzip
 ---------------------------------------------------
 
 'Multiple algorithms'
@@ -438,16 +493,22 @@ extraction of the uncompressed data.
      compressed blocks.
 
 'Optional CRC for the header'
-     Using an optional checksum for the header is not only a bad idea,
-     it is an error; it may prevent the extraction of perfectly good
-     data. For example, if the checksum is used and the bit enabling it
-     is reset by a bit-flip, the header will appear to be intact (in
-     spite of being corrupt) while the compressed blocks will appear to
-     be totally unrecoverable (in spite of being intact). Very
-     misleading indeed.
-
-
-3.1.2 Lzip format improvements over gzip and bzip2
+     Using an optional CRC for the header is not only a bad idea, it is
+     an error; it circumvents the HD of the CRC and may prevent the
+     extraction of perfectly good data. For example, if the CRC is used
+     and the bit enabling it is reset by a bit flip, the header will
+     appear to be intact (in spite of being corrupt) while the
+     compressed blocks will appear to be totally unrecoverable (in
+     spite of being intact). Very misleading indeed.
+
+'Metadata'
+     The gzip format stores some metadata, like the modification time
+     of the original file or the operating system on which compression
+     took place.  This complicates reproducible compression (obtaining
+     identical compressed output from identical input).
+
+
+4.1.2 Lzip format improvements over gzip and bzip2
 --------------------------------------------------
 
 '64-bit size field'
@@ -475,7 +536,7 @@ extraction of the uncompressed data.
      total uncompressed size.
 
 
-3.2 Quality of implementation
+4.2 Quality of implementation
 =============================
 
 'Accurate and robust error detection'
@@ -521,7 +582,7 @@ extraction of the uncompressed data.
 
 File: clzip.info,  Node: File format,  Next: Algorithm,  Prev: Quality assurance,  Up: Top
 
-4 File format
+5 File format
 *************
 
 Perfection is reached, not when there is no longer anything to add, but
@@ -592,7 +653,7 @@ additional information before, between, or after them.
 
 File: clzip.info,  Node: Algorithm,  Next: Stream format,  Prev: File format,  Up: Top
 
-5 Algorithm
+6 Algorithm
 ***********
 
 In spite of its name (Lempel-Ziv-Markov chain-Algorithm), LZMA is not a
@@ -658,7 +719,7 @@ LZMA), and Julian Seward (for bzip2's CLI).
 
 File: clzip.info,  Node: Stream format,  Next: Trailing data,  Prev: Algorithm,  Up: Top
 
-6 Format of the LZMA stream in lzip files
+7 Format of the LZMA stream in lzip files
 *****************************************
 
 The LZMA algorithm has three parameters, called "special LZMA
@@ -698,7 +759,7 @@ the lzip download directory. The source code of lzd is included in
 appendix A.  *Note Reference source code::.
 
 
-6.1 What is coded
+7.1 What is coded
 =================
 
 The LZMA stream includes literals, matches and repeated matches (matches
@@ -773,7 +834,7 @@ slot + direct_bits                   distances from 4 to 127
 slot + (direct_bits - 4) + 4 bits    distances from 128 to 2^32 - 1
 
 
-6.2 The coding contexts
+7.2 The coding contexts
 =======================
 
 These contexts ('Bit_model' in the source), are integers or arrays of
@@ -863,7 +924,7 @@ difference is found, the rest of the byte is decoded using the normal
 bit tree context. (See 'decode_matched' in the source).
 
 
-6.3 The range decoder
+7.3 The range decoder
 =====================
 
 The LZMA stream is consumed one byte at a time by the range decoder.
@@ -883,7 +944,7 @@ range decoder. This is done by shifting 5 bytes in the initialization of
 source).
 
 
-6.4 Decoding the LZMA stream
+7.4 Decoding the LZMA stream
 ============================
 
 After decoding the member header and obtaining the dictionary size, the
@@ -896,7 +957,7 @@ Stream" marker is decoded.
 
 File: clzip.info,  Node: Trailing data,  Next: Examples,  Prev: Stream format,  Up: Top
 
-7 Extra data appended to the file
+8 Extra data appended to the file
 *********************************
 
 Sometimes extra data are found appended to a lzip file after the last
@@ -908,10 +969,11 @@ member. Such trailing data may be:
 
    * Useful data added by the user; a cryptographically secure hash, a
      description of file contents, etc. It is safe to append any amount
-     of text to a lzip file as long as the text does not begin with the
-     string "LZIP", and does not contain any zero bytes (null
-     characters). Nonzero bytes and zero bytes can't be safely mixed in
-     trailing data.
+     of text to a lzip file as long as none of the first four bytes of
+     the text match the corresponding byte in the string "LZIP", and
+     the text does not contain any zero bytes (null characters).
+     Nonzero bytes and zero bytes can't be safely mixed in trailing
+     data.
 
    * Garbage added by some not totally successful copy operation.
 
@@ -919,12 +981,17 @@ member. Such trailing data may be:
      and hash value (for a chosen hash) coincide with those of another
      file.
 
-   * In very rare cases, trailing data could be the corrupt header of
-     another member. In multimember or concatenated files the
-     probability of corruption happening in the magic bytes is 5 times
-     smaller than the probability of getting a false positive caused by
-     the corruption of the integrity information itself. Therefore it
-     can be considered to be below the noise level.
+   * In rare cases, trailing data could be the corrupt header of another
+     member. In multimember or concatenated files the probability of
+     corruption happening in the magic bytes is 5 times smaller than the
+     probability of getting a false positive caused by the corruption
+     of the integrity information itself. Therefore it can be
+     considered to be below the noise level. Additionally, the test
+     used by clzip to discriminate trailing data from a corrupt header
+     has a Hamming distance (HD) of 3, and the 3 bit flips must happen
+     in different magic bytes for the test to fail. In any case, the
+     option '--trailing-error' guarantees that any corrupt header will
+     be detected.
 
    Trailing data are in no way part of the lzip file format, but tools
 reading lzip files are expected to behave as correctly and usefully as
@@ -938,7 +1005,7 @@ cases where a file containing trailing data must be rejected, the option
 
 File: clzip.info,  Node: Examples,  Next: Problems,  Prev: Trailing data,  Up: Top
 
-8 A small tutorial with examples
+9 A small tutorial with examples
 ********************************
 
 WARNING! Even if clzip is bug-free, other causes may result in a corrupt
@@ -1020,8 +1087,8 @@ file with a member size of 32 MiB.
 
 File: clzip.info,  Node: Problems,  Next: Reference source code,  Prev: Examples,  Up: Top
 
-9 Reporting bugs
-****************
+10 Reporting bugs
+*****************
 
 There are probably bugs in clzip. There are certainly errors and
 omissions in this manual. If you report them, they will get fixed. If
@@ -1039,7 +1106,7 @@ Appendix A Reference source code
 ********************************
 
 /*  Lzd - Educational decompressor for the lzip format
-    Copyright (C) 2013-2017 Antonio Diaz Diaz.
+    Copyright (C) 2013-2018 Antonio Diaz Diaz.
 
     This program is free software. Redistribution and use in source and
     binary forms, with or without modification, are permitted provided
@@ -1355,9 +1422,9 @@ bool LZ_decoder::decode_member()		// Returns false if error
   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
+  unsigned rep0 = 0;		// rep[0-3] latest four distances
+  unsigned rep1 = 0;		// used for efficient coding of
+  unsigned rep2 = 0;		// repeated distances
   unsigned rep3 = 0;
   State state;
 
@@ -1452,7 +1519,7 @@ int main( const int argc, const char * const argv[] )
                  "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) 2017 Antonio Diaz Diaz.\n"
+                 "\nCopyright (C) 2018 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"
@@ -1497,7 +1564,7 @@ int main( const int argc, const char * const argv[] )
     }
 
   if( std::fclose( stdout ) != 0 )
-    { std::fprintf( stderr, "Can't close stdout: %s\n", std::strerror( errno ) );
+    { std::fprintf( stderr, "Error closing stdout: %s\n", std::strerror( errno ) );
       return 1; }
   return 0;
   }
@@ -1520,6 +1587,7 @@ Concept index
 * introduction:                          Introduction.          (line 6)
 * invoking:                              Invoking clzip.        (line 6)
 * options:                               Invoking clzip.        (line 6)
+* output:                                Output.                (line 6)
 * quality assurance:                     Quality assurance.     (line 6)
 * reference source code:                 Reference source code. (line 6)
 * trailing data:                         Trailing data.         (line 6)
@@ -1530,19 +1598,20 @@ Concept index
 
 Tag Table:
 Node: Top210
-Node: Introduction1154
-Node: Invoking clzip6630
-Ref: --trailing-error7202
-Node: Quality assurance14125
-Node: File format22281
-Node: Algorithm24686
-Node: Stream format27516
-Node: Trailing data38257
-Node: Examples40159
-Ref: concat-example41341
-Node: Problems42386
-Node: Reference source code42920
-Node: Concept index57238
+Node: Introduction1210
+Node: Output6491
+Node: Invoking clzip8011
+Ref: --trailing-error8577
+Node: Quality assurance16230
+Node: File format24640
+Node: Algorithm27045
+Node: Stream format29875
+Node: Trailing data40616
+Node: Examples42894
+Ref: concat-example44076
+Node: Problems45121
+Node: Reference source code45657
+Node: Concept index59974
 
 End Tag Table
 
diff --git a/doc/clzip.texi b/doc/clzip.texi
index 2cac199..64e09e2 100644
--- a/doc/clzip.texi
+++ b/doc/clzip.texi
@@ -6,8 +6,8 @@
 @finalout
 @c %**end of header
 
-@set UPDATED 13 April 2017
-@set VERSION 1.9
+@set UPDATED 6 February 2018
+@set VERSION 1.10
 
 @dircategory Data Compression
 @direntry
@@ -36,6 +36,7 @@ This manual is for Clzip (version @value{VERSION}, @value{UPDATED}).
 
 @menu
 * Introduction::           Purpose and features of clzip
+* Output::                 Meaning of clzip's output
 * Invoking clzip::         Command line interface
 * Quality assurance::      Design, development and testing of lzip
 * File format::            Detailed format of the compressed file
@@ -49,7 +50,7 @@ This manual is for Clzip (version @value{VERSION}, @value{UPDATED}).
 @end menu
 
 @sp 1
-Copyright @copyright{} 2010-2017 Antonio Diaz Diaz.
+Copyright @copyright{} 2010-2018 Antonio Diaz Diaz.
 
 This manual is free documentation: you have unlimited permission
 to copy, distribute and modify it.
@@ -79,7 +80,7 @@ availability:
 The lzip format provides very safe integrity checking and some data
 recovery means. The
 @uref{http://www.nongnu.org/lzip/manual/lziprecover_manual.html#Data-safety,,lziprecover}
-program can repair bit-flip errors (one of the most common forms of data
+program can repair bit flip errors (one of the most common forms of data
 corruption) in lzip files, and provides data recovery capabilities,
 including error-checked merging of damaged copies of a file.
 @ifnothtml
@@ -128,9 +129,9 @@ choice of dictionary size limit.
 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
 limit, else 2) plus 9 times the dictionary size really used. The option
-@samp{-0} is special and only requires about 1.5 MiB at most. The amount
-of memory required for decompression is about 46 kB larger than the
-dictionary size really used.
+@samp{-0} is special and only requires about @w{1.5 MiB} at most. The
+amount of memory required for decompression is about @w{46 kB} larger
+than the dictionary size really used.
 
 When compressing, clzip replaces every file given in the command line
 with a compressed version of itself, with the name "original_name.lz".
@@ -159,7 +160,7 @@ incomprehensible and therefore pointless.
 
 Clzip will correctly decompress a file which is the concatenation of two
 or more compressed files. The result is the concatenation of the
-corresponding uncompressed files. Integrity testing of concatenated
+corresponding decompressed files. Integrity testing of concatenated
 compressed files is also supported.
 
 Clzip can produce multimember files, and lziprecover can safely recover
@@ -170,7 +171,53 @@ compressed tar archives.
 
 Clzip is able to compress and decompress streams of unlimited size by
 automatically creating multimember output. The members so created are
-large, about 2 PiB each.
+large, about @w{2 PiB} each.
+
+
+@node Output
+@chapter Meaning of clzip's output
+@cindex output
+
+The output of clzip looks like this:
+
+@example
+clzip -v foo
+  foo:  6.676:1, 14.98% ratio, 85.02% saved, 450560 in, 67493 out.
+
+clzip -tvv foo.lz
+  foo.lz:  6.676:1, 14.98% ratio, 85.02% saved.  ok
+@end example
+
+The meaning of each field is as follows:
+
+@table @code
+@item N:1
+The compression ratio @w{(uncompressed_size / compressed_size)}, shown
+as N to 1.
+
+@item ratio
+The inverse compression ratio @w{(compressed_size / uncompressed_size)},
+shown as a percentage. A decimal ratio is easily obtained by moving the
+decimal point two places to the left; @w{14.98% = 0.1498}.
+
+@item saved
+The space saved by compression @w{(1 - ratio)}, shown as a percentage.
+
+@item in
+The size of the uncompressed data. When decompressing or testing, it is
+shown as @code{decompressed}. Note that clzip always prints the
+uncompressed size before the compressed size when compressing,
+decompressing, testing or listing.
+
+@item out
+The size of the compressed data. When decompressing or testing, it is
+shown as @code{compressed}.
+
+@end table
+
+When decompressing or testing at verbosity level 4 (-vvvv), the
+dictionary size used to compress the file and the CRC32 of the
+uncompressed data are also shown.
 
 LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may never
 have been compressed. Decompressed is used to refer to data which have
@@ -195,7 +242,7 @@ clzip [@var{options}] [@var{files}]
 mixed with other @var{files} and is read just once, the first time it
 appears in the command line.
 
-Clzip supports the following options:
+clzip supports the following options:
 
 @table @code
 @item -h
@@ -215,24 +262,24 @@ garbage that can be safely ignored. @xref{concat-example}.
 
 @item -b @var{bytes}
 @itemx --member-size=@var{bytes}
-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 2 PiB. Defaults to 2 PiB.
+When compressing, 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 @w{100 kB} to @w{2 PiB}. Defaults to @w{2 PiB}.
 
 @item -c
 @itemx --stdout
 Compress or decompress to standard output; keep input files unchanged.
 If compressing several files, each file is compressed independently.
 This option is needed when reading from a named pipe (fifo) or from a
-device. Use it also to recover as much of the uncompressed data as
+device. Use it also to recover as much of the decompressed data as
 possible when decompressing a corrupt file.
 
 @item -d
 @itemx --decompress
-Decompress the specified file(s). If a file does not exist or can't be
+Decompress the specified files. If a file does not exist or can't be
 opened, clzip continues decompressing the rest of the files. If a file
-fails to decompress, clzip exits immediately without decompressing the
-rest of the files.
+fails to decompress, or is a terminal, clzip exits immediately without
+decompressing the rest of the files.
 
 @item -f
 @itemx --force
@@ -240,8 +287,8 @@ Force overwrite of output files.
 
 @item -F
 @itemx --recompress
-Force re-compression of files whose name already has the @samp{.lz} or
-@samp{.tlz} suffix.
+When compressing, force re-compression of files whose name already has
+the @samp{.lz} or @samp{.tlz} suffix.
 
 @item -k
 @itemx --keep
@@ -250,7 +297,7 @@ Keep (don't delete) input files during compression or decompression.
 @item -l
 @itemx --list
 Print the uncompressed size, compressed size and percentage saved of the
-specified file(s). Trailing data are ignored. The values produced are
+specified files. Trailing data are ignored. The values produced are
 correct even for multimember files. If more than one file is given, a
 final line containing the cumulative sizes is printed. With @samp{-v},
 the dictionary size, the number of members in the file, and the amount
@@ -263,18 +310,21 @@ verifies that none of the specified files contain trailing data.
 
 @item -m @var{bytes}
 @itemx --match-length=@var{bytes}
-Set the match length limit in bytes. After a match this long is found,
-the search is finished. Valid values range from 5 to 273. Larger values
-usually give better compression ratios but longer compression times.
+When compressing, set the match length limit in bytes. After a match
+this long is found, the search is finished. Valid values range from 5 to
+273. Larger values usually give better compression ratios but longer
+compression times.
 
 @item -o @var{file}
 @itemx --output=@var{file}
 When reading from standard input and @samp{--stdout} has not been
 specified, use @samp{@var{file}} as the virtual name of the uncompressed
-file. This produces a file named @samp{@var{file}} when decompressing, a
-file named @samp{@var{file}.lz} when compressing, and several files
-named @samp{@var{file}00001.lz}, @samp{@var{file}00002.lz}, etc, when
-compressing and splitting the output in volumes.
+file. This produces a file named @samp{@var{file}} when decompressing,
+or a file named @samp{@var{file}.lz} when compressing. A second
+@samp{.lz} extension is not added if @samp{@var{file}} already ends in
+@samp{.lz} or @samp{.tlz}. When compressing and splitting the output in
+volumes, several files named @samp{@var{file}00001.lz},
+@samp{@var{file}00002.lz}, etc, are created.
 
 @item -q
 @itemx --quiet
@@ -282,12 +332,12 @@ Quiet operation. Suppress all messages.
 
 @item -s @var{bytes}
 @itemx --dictionary-size=@var{bytes}
-Set the dictionary size limit in bytes. Clzip will use the smallest
-possible dictionary size for each file without exceeding this limit.
-Valid values range from 4 KiB to 512 MiB. Values 12 to 29 are
-interpreted as powers of two, meaning 2^12 to 2^29 bytes. 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
+When compressing, set the dictionary size limit in bytes. Clzip will use
+the smallest possible dictionary size for each file without exceeding
+this limit. Valid values range from @w{4 KiB} to @w{512 MiB}. Values 12
+to 29 are interpreted as powers of two, meaning 2^12 to 2^29 bytes. 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
 @w{(@var{bytes} / 8)} to it.
 
 For maximum compression you should use a dictionary size limit as large
@@ -296,37 +346,40 @@ is affected at compression time by the choice of dictionary size limit.
 
 @item -S @var{bytes}
 @itemx --volume-size=@var{bytes}
-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
-multimember, 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.
+When compressing, 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}. Input files are kept
+unchanged. Each volume is a complete, maybe multimember, lzip file. A
+small volume size may degrade compression ratio, so use it only when
+needed. Valid values range from @w{100 kB} to @w{4 EiB}.
 
 @item -t
 @itemx --test
-Check integrity of the specified file(s), but don't decompress them.
-This really performs a trial decompression and throws away the result.
-Use it together with @samp{-v} to see information about the file(s). If
-a file fails the test, does not exist, can't be opened, or is a
-terminal, clzip continues checking the rest of the files.
+Check integrity of the specified files, but don't decompress them. This
+really performs a trial decompression and throws away the result. Use it
+together with @samp{-v} to see information about the files. If a file
+fails the test, does not exist, can't be opened, or is a terminal, clzip
+continues checking the rest of the files. A final diagnostic is shown at
+verbosity level 1 or higher if any file fails the test when testing
+multiple files.
 
 @item -v
 @itemx --verbose
 Verbose mode.@*
-When compressing, show the compression ratio for each file processed. A
-second @samp{-v} shows the progress of compression.@*
+When compressing, show the compression ratio and size for each file
+processed.@*
 When decompressing or testing, further -v's (up to 4) increase the
 verbosity level, showing status, compression ratio, dictionary size,
 trailer contents (CRC, data size, member size), and up to 6 bytes of
 trailing data (if any) both in hexadecimal and as a string of printable
-ASCII characters.
+ASCII characters.@*
+Two or more @samp{-v} options show the progress of (de)compression.
 
 @item -0 .. -9
 Set the compression parameters (dictionary size and match length limit)
 as shown in the table below. The default compression level is @samp{-6}.
 Note that @samp{-9} can be much slower than @samp{-0}. These options
-have no effect when decompressing.
+have no effect when decompressing, testing or listing.
 
 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,
@@ -351,6 +404,12 @@ etc, you may need to use the @samp{--dictionary-size} and
 @itemx --best
 Aliases for GNU gzip compatibility.
 
+@item --loose-trailing
+When decompressing, testing or listing, allow trailing data whose first
+bytes are so similar to the magic bytes of a lzip header that they can
+be confused with a corrupt header. Use this option if a file triggers a
+"corrupt header" error and the cause is not indeed a corrupt header.
+
 @end table
 
 Numbers given as arguments to options may be followed by a multiplier
@@ -410,7 +469,7 @@ of gzip.
 
 Probably the worst defect of the gzip format from the point of view of
 data safety is the variable size of its header. If the byte at offset 3
-(flags) of a gzip member gets corrupted, it may become very difficult to
+(flags) of a gzip member gets corrupted, it may become difficult to
 recover the data, even if the compressed blocks are intact, because it
 can't be known with certainty where the compressed blocks begin.
 
@@ -431,22 +490,21 @@ distance larger than the dictionary size acts as a forbidden symbol,
 allowing the decompressor to detect the approximate position of errors,
 and leaving very little work for the check sequence (CRC and data sizes)
 in the detection of errors. Lzip is usually able to detect all posible
-bit-flips in the compressed data without resorting to the check
-sequence. It would be very difficult to write an automatic recovery tool
-like lziprecover for the gzip format. And, as far as I know, it has
-never been written.
+bit flips in the compressed data without resorting to the check
+sequence. It would be difficult to write an automatic recovery tool like
+lziprecover for the gzip format. And, as far as I know, it has never
+been written.
 
 Lzip, like gzip and bzip2, uses a CRC32 to check the integrity of the
 decompressed data because it provides more accurate error detection than
-CRC64 up to a compressed size of about 16 GiB, a size larger than that
-of most files. In the case of lzip, the additional detection capability
-of the decompressor reduces the probability of undetected errors more
-than a million times, making CRC32 more accurate than CRC64 up to about
-20 PiB of compressed size.
+CRC64 up to a compressed size of about @w{16 GiB}, a size larger than
+that of most files. In the case of lzip, the additional detection
+capability of the decompressor reduces the probability of undetected
+errors more than a million times beyond what the CRC32 alone provides.
 
 The lzip format is designed for long-term archiving. Therefore it
 excludes any unneeded features that may interfere with the future
-extraction of the uncompressed data.
+extraction of the decompressed data.
 
 @sp 1
 @subsection Gzip format (mis)features not present in lzip
@@ -472,12 +530,20 @@ header CRC nor the compressed blocks.
 
 @item Optional CRC for the header
 
-Using an optional checksum for the header is not only a bad idea, it is
-an error; it may prevent the extraction of perfectly good data. For
-example, if the checksum is used and the bit enabling it is reset by a
-bit-flip, the header will appear to be intact (in spite of being
-corrupt) while the compressed blocks will appear to be totally
-unrecoverable (in spite of being intact). Very misleading indeed.
+Using an optional CRC for the header is not only a bad idea, it is an
+error; it circumvents the HD of the CRC and may prevent the extraction
+of perfectly good data. For example, if the CRC is used and the bit
+enabling it is reset by a bit flip, the header will appear to be intact
+(in spite of being corrupt) while the compressed blocks will appear to
+be totally unrecoverable (in spite of being intact). Very misleading
+indeed.
+
+@item Metadata
+
+The gzip format stores some metadata, like the modification time of the
+original file or the operating system on which compression took place.
+This complicates reproducible compression (obtaining identical
+compressed output from identical input).
 
 @end table
 
@@ -488,7 +554,7 @@ unrecoverable (in spite of being intact). Very misleading indeed.
 
 Probably the most frequently reported shortcoming of the gzip format is
 that it only stores the least significant 32 bits of the uncompressed
-size. The size of any file larger than 4 GiB gets truncated.
+size. The size of any file larger than @w{4 GiB} gets truncated.
 
 Bzip2 does not store the uncompressed size of the file.
 
@@ -965,9 +1031,10 @@ padding zero bytes to a lzip file.
 @item
 Useful data added by the user; a cryptographically secure hash, a
 description of file contents, etc. It is safe to append any amount of
-text to a lzip file as long as the text does not begin with the string
-"LZIP", and does not contain any zero bytes (null characters). Nonzero
-bytes and zero bytes can't be safely mixed in trailing data.
+text to a lzip file as long as none of the first four bytes of the text
+match the corresponding byte in the string "LZIP", and the text does not
+contain any zero bytes (null characters). Nonzero bytes and zero bytes
+can't be safely mixed in trailing data.
 
 @item
 Garbage added by some not totally successful copy operation.
@@ -977,12 +1044,16 @@ Malicious data added to the file in order to make its total size and
 hash value (for a chosen hash) coincide with those of another file.
 
 @item
-In very rare cases, trailing data could be the corrupt header of another
+In rare cases, trailing data could be the corrupt header of another
 member. In multimember or concatenated files the probability of
 corruption happening in the magic bytes is 5 times smaller than the
 probability of getting a false positive caused by the corruption of the
 integrity information itself. Therefore it can be considered to be below
-the noise level.
+the noise level. Additionally, the test used by clzip to discriminate
+trailing data from a corrupt header has a Hamming distance (HD) of 3,
+and the 3 bit flips must happen in different magic bytes for the test to
+fail. In any case, the option @samp{--trailing-error} guarantees that
+any corrupt header will be detected.
 @end itemize
 
 Trailing data are in no way part of the lzip file format, but tools
@@ -1018,7 +1089,7 @@ clzip -v file
 @sp 1
 @noindent
 Example 2: Like example 1 but the created @samp{file.lz} is multimember
-with a member size of 1 MiB. The compression ratio is not shown.
+with a member size of @w{1 MiB}. The compression ratio is not shown.
 
 @example
 clzip -b 1MiB file
@@ -1067,7 +1138,7 @@ Do this instead
 
 @sp 1
 @noindent
-Example 7: Decompress @samp{file.lz} partially until 10 KiB of
+Example 7: Decompress @samp{file.lz} partially until @w{10 KiB} of
 decompressed data are produced.
 
 @example
@@ -1086,7 +1157,7 @@ clzip -cd file.lz | dd bs=1000 skip=10 count=5
 @sp 1
 @noindent
 Example 9: Create a multivolume compressed tar archive with a volume
-size of 1440 KiB.
+size of @w{1440 KiB}.
 
 @example
 tar -c some_directory | clzip -S 1440KiB -o volume_name
@@ -1103,8 +1174,8 @@ clzip -cd volume_name*.lz | tar -xf -
 @sp 1
 @noindent
 Example 11: Create a multivolume compressed backup of a large database
-file with a volume size of 650 MB, where each volume is a multimember
-file with a member size of 32 MiB.
+file with a volume size of @w{650 MB}, where each volume is a
+multimember file with a member size of @w{32 MiB}.
 
 @example
 clzip -b 32MiB -S 650MB big_db
@@ -1132,7 +1203,7 @@ find by running @w{@code{clzip --version}}.
 
 @verbatim
 /*  Lzd - Educational decompressor for the lzip format
-    Copyright (C) 2013-2017 Antonio Diaz Diaz.
+    Copyright (C) 2013-2018 Antonio Diaz Diaz.
 
     This program is free software. Redistribution and use in source and
     binary forms, with or without modification, are permitted provided
@@ -1448,9 +1519,9 @@ bool LZ_decoder::decode_member()		// Returns false if error
   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
+  unsigned rep0 = 0;		// rep[0-3] latest four distances
+  unsigned rep1 = 0;		// used for efficient coding of
+  unsigned rep2 = 0;		// repeated distances
   unsigned rep3 = 0;
   State state;
 
@@ -1545,7 +1616,7 @@ int main( const int argc, const char * const argv[] )
                  "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) 2017 Antonio Diaz Diaz.\n"
+                 "\nCopyright (C) 2018 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"
@@ -1590,7 +1661,7 @@ int main( const int argc, const char * const argv[] )
     }
 
   if( std::fclose( stdout ) != 0 )
-    { std::fprintf( stderr, "Can't close stdout: %s\n", std::strerror( errno ) );
+    { std::fprintf( stderr, "Error closing stdout: %s\n", std::strerror( errno ) );
       return 1; }
   return 0;
   }
diff --git a/encoder.c b/encoder.c
index 4b9d7ec..e9d2bb5 100644
--- a/encoder.c
+++ b/encoder.c
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
diff --git a/encoder.h b/encoder.h
index c65022a..431ab84 100644
--- a/encoder.h
+++ b/encoder.h
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -280,14 +280,14 @@ static inline bool LZe_init( struct LZ_encoder * const e,
                              const int dict_size, const int len_limit,
                              const int ifd, const int outfd )
   {
-  enum { before = max_num_trials,
+  enum { before_size = max_num_trials,
          /* bytes to keep in buffer after pos */
          after_size = ( 2 * max_match_len ) + 1,
          dict_factor = 2,
          num_prev_positions23 = num_prev_positions2 + num_prev_positions3,
          pos_array_factor = 2 };
 
-  if( !LZeb_init( &e->eb, before, dict_size, after_size, dict_factor,
+  if( !LZeb_init( &e->eb, before_size, dict_size, after_size, dict_factor,
                   num_prev_positions23, pos_array_factor, ifd, outfd ) )
     return false;
   e->cycles = ( len_limit < max_match_len ) ? 16 + ( len_limit / 2 ) : 256;
diff --git a/encoder_base.c b/encoder_base.c
index e384d22..019a162 100644
--- a/encoder_base.c
+++ b/encoder_base.c
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -69,21 +69,22 @@ void Mb_normalize_pos( struct Matchfinder_base * const mb )
   }
 
 
-bool Mb_init( struct Matchfinder_base * const mb, const int before,
+bool Mb_init( struct Matchfinder_base * const mb, const int before_size,
               const int dict_size, const int after_size,
               const int dict_factor, const int num_prev_positions23,
               const int pos_array_factor, const int ifd )
   {
   const int buffer_size_limit =
-    ( dict_factor * dict_size ) + before + after_size;
+    ( dict_factor * dict_size ) + before_size + after_size;
   unsigned size;
   int i;
 
   mb->partial_data_pos = 0;
-  mb->before_size = before;
+  mb->before_size = before_size;
   mb->pos = 0;
   mb->cyclic_pos = 0;
   mb->stream_pos = 0;
+  mb->num_prev_positions23 = num_prev_positions23;
   mb->infd = ifd;
   mb->at_stream_end = false;
 
@@ -111,8 +112,8 @@ bool Mb_init( struct Matchfinder_base * const mb, const int before,
     size >>= 1;
   mb->key4_mask = size - 1;
   size += num_prev_positions23;
-
   mb->num_prev_positions = size;
+
   mb->pos_array_size = pos_array_factor * ( mb->dictionary_size + 1 );
   size += mb->pos_array_size;
   if( size * sizeof mb->prev_positions[0] <= size ) mb->prev_positions = 0;
@@ -134,8 +135,20 @@ void Mb_reset( struct Matchfinder_base * const mb )
   mb->stream_pos -= mb->pos;
   mb->pos = 0;
   mb->cyclic_pos = 0;
-  for( i = 0; i < mb->num_prev_positions; ++i ) mb->prev_positions[i] = 0;
   Mb_read_block( mb );
+  if( mb->at_stream_end && mb->stream_pos < mb->dictionary_size )
+    {
+    int size;
+    mb->dictionary_size = max( min_dictionary_size, mb->stream_pos );
+    size = 1 << max( 16, real_bits( mb->dictionary_size - 1 ) - 2 );
+    if( mb->dictionary_size > 1 << 26 )		/* 64 MiB */
+      size >>= 1;
+    mb->key4_mask = size - 1;
+    size += mb->num_prev_positions23;
+    mb->num_prev_positions = size;
+    mb->pos_array = mb->prev_positions + mb->num_prev_positions;
+    }
+  for( i = 0; i < mb->num_prev_positions; ++i ) mb->prev_positions[i] = 0;
   }
 
 
@@ -148,7 +161,7 @@ void Re_flush_data( struct Range_encoder * const renc )
       { show_error( "Write error", errno, false ); cleanup_and_fail( 1 ); }
     renc->partial_member_pos += renc->pos;
     renc->pos = 0;
-    show_progress( 0, 0, 0, 0 );
+    show_cprogress( 0, 0, 0, 0 );
     }
   }
 
@@ -188,5 +201,5 @@ void LZeb_reset( struct LZ_encoder_base * const eb )
   Bm_array_init( eb->bm_align, dis_align_size );
   Lm_init( &eb->match_len_model );
   Lm_init( &eb->rep_len_model );
-  Re_reset( &eb->renc );
+  Re_reset( &eb->renc, eb->mb.dictionary_size );
   }
diff --git a/encoder_base.h b/encoder_base.h
index b2985f1..c574dcc 100644
--- a/encoder_base.h
+++ b/encoder_base.h
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -170,6 +170,7 @@ struct Matchfinder_base
   int stream_pos;		/* first byte not yet read from file */
   int pos_limit;		/* when reached, a new block must be read */
   int key4_mask;
+  int num_prev_positions23;
   int num_prev_positions;	/* size of prev_positions */
   int pos_array_size;
   int infd;			/* input file descriptor */
@@ -179,7 +180,7 @@ struct Matchfinder_base
 bool Mb_read_block( struct Matchfinder_base * const mb );
 void Mb_normalize_pos( struct Matchfinder_base * const mb );
 
-bool Mb_init( struct Matchfinder_base * const mb, const int before,
+bool Mb_init( struct Matchfinder_base * const mb, const int before_size,
               const int dict_size, const int after_size,
               const int dict_factor, const int num_prev_positions23,
               const int pos_array_factor, const int ifd );
@@ -262,7 +263,8 @@ static inline void Re_shift_low( struct Range_encoder * const renc )
   renc->low = ( renc->low & 0x00FFFFFFU ) << 8;
   }
 
-static inline void Re_reset( struct Range_encoder * const renc )
+static inline void Re_reset( struct Range_encoder * const renc,
+                             const unsigned dictionary_size )
   {
   int i;
   renc->low = 0;
@@ -271,6 +273,7 @@ static inline void Re_reset( struct Range_encoder * const renc )
   renc->range = 0xFFFFFFFFU;
   renc->ff_count = 0;
   renc->cache = 0;
+  Fh_set_dictionary_size( renc->header, dictionary_size );
   for( i = 0; i < Fh_size; ++i )
     Re_put_byte( renc, renc->header[i] );
   }
@@ -282,8 +285,7 @@ static inline bool Re_init( struct Range_encoder * const renc,
   if( !renc->buffer ) return false;
   renc->outfd = ofd;
   Fh_set_magic( renc->header );
-  Fh_set_dictionary_size( renc->header, dictionary_size );
-  Re_reset( renc );
+  Re_reset( renc, dictionary_size );
   return true;
   }
 
@@ -445,13 +447,13 @@ struct LZ_encoder_base
 void LZeb_reset( struct LZ_encoder_base * const eb );
 
 static inline bool LZeb_init( struct LZ_encoder_base * const eb,
-                              const int before, const int dict_size,
+                              const int before_size, const int dict_size,
                               const int after_size, const int dict_factor,
                               const int num_prev_positions23,
                               const int pos_array_factor,
                               const int ifd, const int outfd )
   {
-  if( !Mb_init( &eb->mb, before, dict_size, after_size, dict_factor,
+  if( !Mb_init( &eb->mb, before_size, dict_size, after_size, dict_factor,
                 num_prev_positions23, pos_array_factor, ifd ) ) return false;
   if( !Re_init( &eb->renc, eb->mb.dictionary_size, outfd ) ) return false;
   LZeb_reset( eb );
diff --git a/fast_encoder.c b/fast_encoder.c
index 399cc1a..5cd7978 100644
--- a/fast_encoder.c
+++ b/fast_encoder.c
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
diff --git a/fast_encoder.h b/fast_encoder.h
index 9825068..b1ba5ed 100644
--- a/fast_encoder.h
+++ b/fast_encoder.h
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -49,7 +49,7 @@ static inline void FLZe_update_and_move( struct FLZ_encoder * const fe, int n )
 static inline bool FLZe_init( struct FLZ_encoder * const fe,
                               const int ifd, const int outfd )
   {
-  enum { before = 0,
+  enum { before_size = 0,
          dict_size = 65536,
          /* bytes to keep in buffer after pos */
          after_size = max_match_len,
@@ -57,7 +57,7 @@ static inline bool FLZe_init( struct FLZ_encoder * const fe,
          num_prev_positions23 = 0,
          pos_array_factor = 1 };
 
-  return LZeb_init( &fe->eb, before, dict_size, after_size, dict_factor,
+  return LZeb_init( &fe->eb, before_size, dict_size, after_size, dict_factor,
                     num_prev_positions23, pos_array_factor, ifd, outfd );
   }
 
diff --git a/file_index.c b/file_index.c
index 74adf95..1af9a3a 100644
--- a/file_index.c
+++ b/file_index.c
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -108,7 +108,9 @@ static void Fi_set_num_error( struct File_index * const fi,
 
 /* If successful, push last member and set pos to member header. */
 static bool Fi_skip_trailing_data( struct File_index * const fi,
-                                   const int fd, long long * const pos )
+                                   const int fd, long long * const pos,
+                                   const bool ignore_trailing,
+                                   const bool loose_trailing )
   {
   enum { block_size = 16384,
          buffer_size = block_size + Ft_size - 1 + Fh_size };
@@ -152,6 +154,11 @@ static bool Fi_skip_trailing_data( struct File_index * const fi,
           add_error( fi, "Last member in input file is truncated or corrupt." );
           fi->retval = 2; return false;
           }
+        if( !loose_trailing && bsize - i >= Fh_size &&
+            Fh_verify_corrupt( buffer + i ) )
+          { add_error( fi, corrupt_mm_msg ); fi->retval = 2; return false; }
+        if( !ignore_trailing )
+          { add_error( fi, trailing_msg ); fi->retval = 2; return false; }
         *pos = ipos + i - member_size;
         return push_back_member( fi, 0, Ft_get_data_size( *trailer ), *pos,
                                  member_size, dictionary_size );
@@ -170,7 +177,7 @@ static bool Fi_skip_trailing_data( struct File_index * const fi,
 
 
 bool Fi_init( struct File_index * const fi, const int infd,
-              const bool ignore_trailing )
+              const bool ignore_trailing, const bool loose_trailing )
   {
   File_header header;
   long long pos;
@@ -211,12 +218,10 @@ bool Fi_init( struct File_index * const fi, const int infd,
     member_size = Ft_get_member_size( trailer );
     if( member_size < min_member_size || member_size > (unsigned long long)pos )
       {
-      if( fi->members > 0 )
-        Fi_set_num_error( fi, "Member size in trailer is corrupt at pos ",
-                          pos - 8 );
-      else if( Fi_skip_trailing_data( fi, infd, &pos ) )
-        { if( ignore_trailing ) continue;
-          add_error( fi, trailing_msg ); fi->retval = 2; return false; }
+      if( fi->members <= 0 )
+        { if( Fi_skip_trailing_data( fi, infd, &pos, ignore_trailing,
+              loose_trailing ) ) continue; else return false; }
+      Fi_set_num_error( fi, "Member size in trailer is corrupt at pos ", pos - 8 );
       break;
       }
     if( seek_read( infd, header, Fh_size, pos - member_size ) != Fh_size )
@@ -225,11 +230,10 @@ bool Fi_init( struct File_index * const fi, const int infd,
     if( !Fh_verify_magic( header ) || !Fh_verify_version( header ) ||
         !isvalid_ds( dictionary_size ) )
       {
-      if( fi->members > 0 )
-        Fi_set_num_error( fi, "Bad header at pos ", pos - member_size );
-      else if( Fi_skip_trailing_data( fi, infd, &pos ) )
-        { if( ignore_trailing ) continue;
-          add_error( fi, trailing_msg ); fi->retval = 2; return false; }
+      if( fi->members <= 0 )
+        { if( Fi_skip_trailing_data( fi, infd, &pos, ignore_trailing,
+              loose_trailing ) ) continue; else return false; }
+      Fi_set_num_error( fi, "Bad header at pos ", pos - member_size );
       break;
       }
     pos -= member_size;
diff --git a/file_index.h b/file_index.h
index d093fa9..ae5c5ce 100644
--- a/file_index.h
+++ b/file_index.h
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -57,7 +57,7 @@ struct File_index
   };
 
 bool Fi_init( struct File_index * const fi, const int infd,
-              const bool ignore_trailing );
+              const bool ignore_trailing, const bool loose_trailing );
 
 void Fi_free( struct File_index * const fi );
 
diff --git a/list.c b/list.c
index c72360d..cc21833 100644
--- a/list.c
+++ b/list.c
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -34,7 +34,7 @@ static void list_line( const unsigned long long uncomp_size,
   {
   if( uncomp_size > 0 )
     printf( "%15llu %15llu %6.2f%%  %s\n", uncomp_size, comp_size,
-            100.0 * ( 1.0 - ( (double)comp_size / uncomp_size ) ),
+            100.0 - ( ( 100.0 * comp_size ) / uncomp_size ),
             input_filename );
   else
     printf( "%15llu %15llu   -INF%%  %s\n", uncomp_size, comp_size,
@@ -43,7 +43,7 @@ static void list_line( const unsigned long long uncomp_size,
 
 
 int list_files( const char * const filenames[], const int num_filenames,
-                const bool ignore_trailing )
+                const bool ignore_trailing, const bool loose_trailing )
   {
   unsigned long long total_comp = 0, total_uncomp = 0;
   int files = 0, retval = 0;
@@ -63,7 +63,7 @@ int list_files( const char * const filenames[], const int num_filenames,
       open_instream( input_filename, &in_stats, true, true );
     if( infd < 0 ) { if( retval < 1 ) retval = 1; continue; }
 
-    Fi_init( &file_index, infd, ignore_trailing );
+    Fi_init( &file_index, infd, ignore_trailing, loose_trailing );
     close( infd );
     if( file_index.retval != 0 )
       {
diff --git a/lzip.h b/lzip.h
index 49b6b93..41784da 100644
--- a/lzip.h
+++ b/lzip.h
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -22,6 +22,8 @@
   #define min(x,y) ((x) <= (y) ? (x) : (y))
 #endif
 
+void * resize_buffer( void * buf, const unsigned min_size );
+
 typedef int State;
 
 enum { states = 12 };
@@ -114,9 +116,13 @@ static inline void Lm_init( struct Len_model * const lm )
   }
 
 
+/* defined in main.c */
+extern int verbosity;
+
 struct Pretty_print
   {
   const char * name;
+  char * padded_name;
   const char * stdin_name;
   unsigned longest_name;
   bool first_post;
@@ -124,11 +130,12 @@ struct Pretty_print
 
 static inline void Pp_init( struct Pretty_print * const pp,
                             const char * const filenames[],
-                            const int num_filenames, const int verbosity )
+                            const int num_filenames )
   {
   unsigned stdin_name_len;
   int i;
   pp->name = 0;
+  pp->padded_name = 0;
   pp->stdin_name = "(stdin)";
   pp->longest_name = 0;
   pp->first_post = false;
@@ -147,9 +154,19 @@ static inline void Pp_init( struct Pretty_print * const pp,
 static inline void Pp_set_name( struct Pretty_print * const pp,
                                 const char * const filename )
   {
+  unsigned name_len, padded_name_len, i = 0;
+
   if( filename && filename[0] && strcmp( filename, "-" ) != 0 )
     pp->name = filename;
   else pp->name = pp->stdin_name;
+  name_len = strlen( pp->name );
+  padded_name_len = max( name_len, pp->longest_name ) + 4;
+  pp->padded_name = resize_buffer( pp->padded_name, padded_name_len + 1 );
+  while( i < 2 ) pp->padded_name[i++] = ' ';
+  while( i < name_len + 2 ) { pp->padded_name[i] = pp->name[i-2]; ++i; }
+  pp->padded_name[i++] = ':';
+  while( i < padded_name_len ) pp->padded_name[i++] = ' ';
+  pp->padded_name[i] = 0;
   pp->first_post = true;
   }
 
@@ -216,12 +233,21 @@ static inline void Fh_set_magic( File_header data )
 static inline bool Fh_verify_magic( const File_header data )
   { return ( memcmp( data, magic_string, 4 ) == 0 ); }
 
-/* detect truncated header */
-static inline bool Fh_verify_prefix( const File_header data, const int size )
+/* detect (truncated) header */
+static inline bool Fh_verify_prefix( const File_header data, const int sz )
   {
-  int i; for( i = 0; i < size && i < 4; ++i )
+  int i; for( i = 0; i < sz && i < 4; ++i )
     if( data[i] != magic_string[i] ) return false;
-  return ( size > 0 );
+  return ( sz > 0 );
+  }
+
+/* detect corrupt header */
+static inline bool Fh_verify_corrupt( const File_header data )
+  {
+  int matches = 0;
+  int i; for( i = 0; i < 4; ++i )
+    if( data[i] == magic_string[i] ) ++matches;
+  return ( matches > 1 && matches < 4 );
   }
 
 static inline uint8_t Fh_version( const File_header data )
@@ -295,6 +321,7 @@ static inline void Ft_set_member_size( File_trailer data, unsigned long long sz
 
 static const char * const bad_magic_msg = "Bad magic number (file not in lzip format).";
 static const char * const bad_dict_msg = "Invalid dictionary size in member header.";
+static const char * const corrupt_mm_msg = "Corrupt header in multimember file.";
 static const char * const trailing_msg = "Trailing data not allowed.";
 
 /* defined in decoder.c */
@@ -303,23 +330,27 @@ int writeblock( const int fd, const uint8_t * const buf, const int size );
 
 /* defined in list.c */
 int list_files( const char * const filenames[], const int num_filenames,
-                const bool ignore_trailing );
+                const bool ignore_trailing, const bool loose_trailing );
 
 /* defined in main.c */
-extern int verbosity;
 struct stat;
 const char * bad_version( const unsigned version );
 const char * format_ds( const unsigned dictionary_size );
+void show_header( const unsigned dictionary_size );
 int open_instream( const char * const name, struct stat * const in_statsp,
                    const bool no_ofile, const bool reg_only );
-void * resize_buffer( void * buf, const unsigned min_size );
 void cleanup_and_fail( const int retval );
 void show_error( const char * const msg, const int errcode, const bool help );
 void show_file_error( const char * const filename, const char * const msg,
                       const int errcode );
 void internal_error( const char * const msg );
 struct Matchfinder_base;
-void show_progress( const unsigned long long partial_size,
-                    const struct Matchfinder_base * const m,
-                    struct Pretty_print * const p,
-                    const unsigned long long cfile_size );
+void show_cprogress( const unsigned long long cfile_size,
+                     const unsigned long long partial_size,
+                     const struct Matchfinder_base * const m,
+                     struct Pretty_print * const p );
+struct Range_decoder;
+void show_dprogress( const unsigned long long cfile_size,
+                     const unsigned long long partial_size,
+                     const struct Range_decoder * const d,
+                     struct Pretty_print * const p );
diff --git a/main.c b/main.c
index 1af09f3..89ba2a7 100644
--- a/main.c
+++ b/main.c
@@ -1,5 +1,5 @@
 /*  Clzip - LZMA lossless data compressor
-    Copyright (C) 2010-2017 Antonio Diaz Diaz.
+    Copyright (C) 2010-2018 Antonio Diaz Diaz.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -71,7 +71,7 @@ int verbosity = 0;
 
 const char * const Program_name = "Clzip";
 const char * const program_name = "clzip";
-const char * const program_year = "2017";
+const char * const program_year = "2018";
 const char * invocation_name = 0;
 
 const struct { const char * from; const char * to; } known_extensions[] = {
@@ -111,12 +111,13 @@ static void show_help( void )
           "  -o, --output=<file>            if reading standard input, write to <file>\n"
           "  -q, --quiet                    suppress all messages\n"
           "  -s, --dictionary-size=<bytes>  set dictionary size limit in bytes [8 MiB]\n"
-          "  -S, --volume-size=<bytes>      set volume size limit in bytes\n"
+          "  -S, --volume-size=<bytes>      set volume size limit in bytes, implies -k\n"
           "  -t, --test                     test compressed file integrity\n"
           "  -v, --verbose                  be verbose (a 2nd -v gives more)\n"
           "  -0 .. -9                       set compression level [default 6]\n"
           "      --fast                     alias for -0\n"
           "      --best                     alias for -9\n"
+          "      --loose-trailing           allow trailing data seeming corrupt header\n"
           "If no file names are given, or if a file is '-', clzip compresses or\n"
           "decompresses from standard input to standard output.\n"
           "Numbers may be followed by a multiplier: k = kB = 10^3 = 1000,\n"
@@ -146,6 +147,35 @@ static void show_version( void )
   }
 
 
+/* assure at least a minimum size for buffer 'buf' */
+void * resize_buffer( void * buf, const unsigned min_size )
+  {
+  if( buf ) buf = realloc( buf, min_size );
+  else buf = malloc( min_size );
+  if( !buf )
+    {
+    show_error( "Not enough memory.", 0, false );
+    cleanup_and_fail( 1 );
+    }
+  return buf;
+  }
+
+
+void Pp_show_msg( struct Pretty_print * const pp, const char * const msg )
+  {
+  if( verbosity >= 0 )
+    {
+    if( pp->first_post )
+      {
+      pp->first_post = false;
+      fputs( pp->padded_name, stderr );
+      if( !msg ) fflush( stderr );
+      }
+    if( msg ) fprintf( stderr, "%s\n", msg );
+    }
+  }
+
+
 const char * bad_version( const unsigned version )
   {
   static char buf[80];
@@ -163,10 +193,10 @@ const char * format_ds( const unsigned dictionary_size )
     { "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi" };
   const char * p = "";
   const char * np = "  ";
-  unsigned num = dictionary_size, i;
+  unsigned num = dictionary_size;
   bool exact = ( num % factor == 0 );
 
-  for( i = 0; i < 8 && ( num > 9999 || ( exact && num >= factor ) ); ++i )
+  int i; for( i = 0; i < 8 && ( num > 9999 || ( exact && num >= factor ) ); ++i )
     { num /= factor; if( num % factor != 0 ) exact = false;
       p = prefix[i]; np = ""; }
   snprintf( buf, bufsize, "%s%4u %sB", np, num, p );
@@ -174,10 +204,9 @@ const char * format_ds( const unsigned dictionary_size )
   }
 
 
-static void show_header( const unsigned dictionary_size )
+void show_header( const unsigned dictionary_size )
   {
-  if( verbosity >= 3 )
-    fprintf( stderr, "dictionary %s.  ", format_ds( dictionary_size ) );
+  fprintf( stderr, "dictionary %s, ", format_ds( dictionary_size ) );
   }
 
 
@@ -271,6 +300,43 @@ static int extension_index( const char * const name )
   }
 
 
+static void set_c_outname( const char * const name, const bool force_ext,
+                           const bool multifile )
+  {
+  output_filename = resize_buffer( output_filename, strlen( name ) + 5 +
+                                   strlen( known_extensions[0].from ) + 1 );
+  strcpy( output_filename, name );
+  if( multifile ) strcat( output_filename, "00001" );
+  if( force_ext || multifile || extension_index( output_filename ) < 0 )
+    strcat( output_filename, known_extensions[0].from );
+  }
+
+
+static void set_d_outname( const char * const name, const int eindex )
+  {
+  const unsigned name_len = strlen( name );
+  if( eindex >= 0 )
+    {
+    const char * const from = known_extensions[eindex].from;
+    const unsigned from_len = strlen( from );
+    if( name_len > from_len )
+      {
+      output_filename = resize_buffer( output_filename, name_len +
+                                       strlen( known_extensions[eindex].to ) + 1 );
+      strcpy( output_filename, name );
+      strcpy( output_filename + name_len - from_len, known_extensions[eindex].to );
+      return;
+      }
+    }
+  output_filename = resize_buffer( output_filename, name_len + 4 + 1 );
+  strcpy( output_filename, name );
+  strcat( output_filename, ".out" );
+  if( verbosity >= 1 )
+    fprintf( stderr, "%s: Can't guess original name for '%s' -- using '%s'\n",
+             program_name, name, output_filename );
+  }
+
+
 int open_instream( const char * const name, struct stat * const in_statsp,
                    const bool no_ofile, const bool reg_only )
   {
@@ -315,55 +381,6 @@ static int open_instream2( const char * const name, struct stat * const in_stats
   }
 
 
-/* assure at least a minimum size for buffer 'buf' */
-void * resize_buffer( void * buf, const unsigned min_size )
-  {
-  if( buf ) buf = realloc( buf, min_size );
-  else buf = malloc( min_size );
-  if( !buf )
-    {
-    show_error( "Not enough memory.", 0, false );
-    cleanup_and_fail( 1 );
-    }
-  return buf;
-  }
-
-
-static void set_c_outname( const char * const name, const bool multifile )
-  {
-  output_filename = resize_buffer( output_filename, strlen( name ) + 5 +
-                                   strlen( known_extensions[0].from ) + 1 );
-  strcpy( output_filename, name );
-  if( multifile ) strcat( output_filename, "00001" );
-  strcat( output_filename, known_extensions[0].from );
-  }
-
-
-static void set_d_outname( const char * const name, const int eindex )
-  {
-  const unsigned name_len = strlen( name );
-  if( eindex >= 0 )
-    {
-    const char * const from = known_extensions[eindex].from;
-    const unsigned from_len = strlen( from );
-    if( name_len > from_len )
-      {
-      output_filename = resize_buffer( output_filename, name_len +
-                                       strlen( known_extensions[eindex].to ) + 1 );
-      strcpy( output_filename, name );
-      strcpy( output_filename + name_len - from_len, known_extensions[eindex].to );
-      return;
-      }
-    }
-  output_filename = resize_buffer( output_filename, name_len + 4 + 1 );
-  strcpy( output_filename, name );
-  strcat( output_filename, ".out" );
-  if( verbosity >= 1 )
-    fprintf( stderr, "%s: Can't guess original name for '%s' -- using '%s'\n",
-             program_name, name, output_filename );
-  }
-
-
 static bool open_outstream( const bool force, const bool from_stdin )
   {
   const mode_t usr_rw = S_IRUSR | S_IWUSR;
@@ -479,14 +496,13 @@ struct Poly_encoder
   };
 
 
-static int compress( const unsigned long long member_size,
+static int compress( const unsigned long long cfile_size,
+                     const unsigned long long member_size,
                      const unsigned long long volume_size, const int infd,
                      const struct Lzma_options * const encoder_options,
                      struct Pretty_print * const pp,
                      const struct stat * const in_statsp, const bool zero )
   {
-  const unsigned long long cfile_size =
-    (in_statsp && S_ISREG( in_statsp->st_mode )) ? in_statsp->st_size / 100 : 0;
   unsigned long long in_size = 0, out_size = 0, partial_volume_size = 0;
   int retval = 0;
   struct Poly_encoder encoder = { 0, 0, 0 };	/* polymorphic encoder */
@@ -524,7 +540,7 @@ static int compress( const unsigned long long member_size,
     {
     const unsigned long long size = ( volume_size > 0 ) ?
       min( member_size, volume_size - partial_volume_size ) : member_size;
-    show_progress( in_size, &encoder.eb->mb, pp, cfile_size );	/* init */
+    show_cprogress( cfile_size, in_size, &encoder.eb->mb, pp );	/* init */
     if( ( zero && !FLZe_encode_member( encoder.fe, size ) ) ||
         ( !zero && !LZe_encode_member( encoder.e, size ) ) )
       { Pp_show_msg( pp, "Encoder error." ); retval = 1; break; }
@@ -554,11 +570,11 @@ static int compress( const unsigned long long member_size,
     if( in_size == 0 || out_size == 0 )
       fputs( " no data compressed.\n", stderr );
     else
-      fprintf( stderr, "%6.3f:1, %6.3f bits/byte, "
-                       "%5.2f%% saved, %llu in, %llu out.\n",
+      fprintf( stderr, "%6.3f:1, %5.2f%% ratio, %5.2f%% saved, "
+                       "%llu in, %llu out.\n",
                (double)in_size / out_size,
-               ( 8.0 * out_size ) / in_size,
-               100.0 * ( 1.0 - ( (double)out_size / in_size ) ),
+               ( 100.0 * out_size ) / in_size,
+               100.0 - ( ( 100.0 * out_size ) / in_size ),
                in_size, out_size );
     }
   LZeb_free( encoder.eb );
@@ -577,9 +593,9 @@ static unsigned char xdigit( const unsigned value )
 
 static bool show_trailing_data( const uint8_t * const data, const int size,
                                 struct Pretty_print * const pp, const bool all,
-                                const bool ignore_trailing )
+                                const int ignore_trailing )	/* -1 = show */
   {
-  if( verbosity >= 4 || !ignore_trailing )
+  if( verbosity >= 4 || ignore_trailing <= 0 )
     {
     int i;
     char buf[80];
@@ -597,14 +613,15 @@ static bool show_trailing_data( const uint8_t * const data, const int size,
     if( len < sizeof buf ) buf[len++] = '\'';
     if( len < sizeof buf ) buf[len] = 0; else buf[sizeof buf - 1] = 0;
     Pp_show_msg( pp, buf );
-    if( !ignore_trailing ) show_file_error( pp->name, trailing_msg, 0 );
+    if( ignore_trailing == 0 ) show_file_error( pp->name, trailing_msg, 0 );
     }
-  return ignore_trailing;
+  return ( ignore_trailing > 0 );
   }
 
 
-static int decompress( const int infd, struct Pretty_print * const pp,
-                       const bool ignore_trailing, const bool testing )
+static int decompress( const unsigned long long cfile_size, const int infd,
+                struct Pretty_print * const pp, const bool ignore_trailing,
+                const bool loose_trailing, const bool testing )
   {
   unsigned long long partial_file_pos = 0;
   struct Range_decoder rdec;
@@ -626,8 +643,12 @@ static int decompress( const int infd, struct Pretty_print * const pp,
     size = Rd_read_data( &rdec, header, Fh_size );
     if( Rd_finished( &rdec ) )			/* End Of File */
       {
-      if( first_member || Fh_verify_prefix( header, size ) )
-        { Pp_show_msg( pp, "File ends unexpectedly at member header." );
+      if( first_member )
+        { show_file_error( pp->name, "File ends unexpectedly at member header.", 0 );
+          retval = 2; }
+      else if( Fh_verify_prefix( header, size ) )
+        { Pp_show_msg( pp, "Truncated header in multimember file." );
+          show_trailing_data( header, size, pp, true, -1 );
           retval = 2; }
       else if( size > 0 && !show_trailing_data( header, size, pp,
                                                 true, ignore_trailing ) )
@@ -638,24 +659,27 @@ static int decompress( const int infd, struct Pretty_print * const pp,
       {
       if( first_member )
         { show_file_error( pp->name, bad_magic_msg, 0 ); retval = 2; }
+      else if( !loose_trailing && Fh_verify_corrupt( header ) )
+        { Pp_show_msg( pp, corrupt_mm_msg );
+          show_trailing_data( header, size, pp, false, -1 );
+          retval = 2; }
       else if( !show_trailing_data( header, size, pp, false, ignore_trailing ) )
         retval = 2;
       break;
       }
     if( !Fh_verify_version( header ) )
-      {
-      Pp_show_msg( pp, bad_version( Fh_version( header ) ) );
-      retval = 2; break;
-      }
+      { Pp_show_msg( pp, bad_version( Fh_version( header ) ) );
+        retval = 2; break; }
     dictionary_size = Fh_get_dictionary_size( header );
     if( !isvalid_ds( dictionary_size ) )
       { Pp_show_msg( pp, bad_dict_msg ); retval = 2; break; }
 
     if( verbosity >= 2 || ( verbosity == 1 && first_member ) )
-      { Pp_show_msg( pp, 0 ); show_header( dictionary_size ); }
+      Pp_show_msg( pp, 0 );
 
     if( !LZd_init( &decoder, &rdec, dictionary_size, outfd ) )
       { Pp_show_msg( pp, "Not enough memory." ); retval = 1; break; }
+    show_dprogress( cfile_size, partial_file_pos, &rdec, pp );	/* init */
     result = LZd_decode_member( &decoder, pp );
     partial_file_pos += Rd_member_position( &rdec );
     LZd_free( &decoder );
@@ -728,25 +752,61 @@ void internal_error( const char * const msg )
   }
 
 
-void show_progress( const unsigned long long partial_size,
-                    const struct Matchfinder_base * const m,
-                    struct Pretty_print * const p,
-                    const unsigned long long cfile_size )
+void show_cprogress( const unsigned long long cfile_size,
+                     const unsigned long long partial_size,
+                     const struct Matchfinder_base * const m,
+                     struct Pretty_print * const p )
   {
   static unsigned long long csize = 0;		/* file_size / 100 */
   static unsigned long long psize = 0;
   static const struct Matchfinder_base * mb = 0;
   static struct Pretty_print * pp = 0;
+  static bool enabled = true;
 
-  if( verbosity < 2 ) return;
-  if( m )					/* initialize static vars */
-    { csize = cfile_size; psize = partial_size; mb = m; pp = p; }
+  if( !enabled ) return;
+  if( p )					/* initialize static vars */
+    {
+    if( verbosity < 2 || !isatty( STDERR_FILENO ) ) { enabled = false; return; }
+    csize = cfile_size; psize = partial_size; mb = m; pp = p;
+    }
   if( mb && pp )
     {
     const unsigned long long pos = psize + Mb_data_position( mb );
     if( csize > 0 )
-      fprintf( stderr, "%4llu%%", pos / csize );
-    fprintf( stderr, "  %.1f MB\r", pos / 1000000.0 );
+      fprintf( stderr, "%4llu%%  %.1f MB\r", pos / csize, pos / 1000000.0 );
+    else
+      fprintf( stderr, "  %.1f MB\r", pos / 1000000.0 );
+    Pp_reset( pp ); Pp_show_msg( pp, 0 );	/* restore cursor position */
+    }
+  }
+
+
+void show_dprogress( const unsigned long long cfile_size,
+                     const unsigned long long partial_size,
+                     const struct Range_decoder * const d,
+                     struct Pretty_print * const p )
+  {
+  static unsigned long long csize = 0;		/* file_size / 100 */
+  static unsigned long long psize = 0;
+  static const struct Range_decoder * rdec = 0;
+  static struct Pretty_print * pp = 0;
+  static int counter = 0;
+  static bool enabled = true;
+
+  if( !enabled ) return;
+  if( p )					/* initialize static vars */
+    {
+    if( verbosity < 2 || !isatty( STDERR_FILENO ) ) { enabled = false; return; }
+    csize = cfile_size; psize = partial_size; rdec = d; pp = p; counter = 0;
+    }
+  if( rdec && pp && --counter <= 0 )
+    {
+    const unsigned long long pos = psize + Rd_member_position( rdec );
+    counter = 7;		/* update display every 114688 bytes */
+    if( csize > 0 )
+      fprintf( stderr, "%4llu%%  %.1f MB\r", pos / csize, pos / 1000000.0 );
+    else
+      fprintf( stderr, "  %.1f MB\r", pos / 1000000.0 );
     Pp_reset( pp ); Pp_show_msg( pp, 0 );	/* restore cursor position */
     }
   }
@@ -758,7 +818,7 @@ int main( const int argc, const char * const argv[] )
      to the corresponding LZMA compression modes. */
   const struct Lzma_options option_mapping[] =
     {
-    { 1 << 16,  16 },		/* -0 entry values not used */
+    { 1 << 16,  16 },		/* -0 */
     { 1 << 20,   5 },		/* -1 */
     { 3 << 19,   6 },		/* -2 */
     { 1 << 21,   8 },		/* -3 */
@@ -776,52 +836,55 @@ int main( const int argc, const char * const argv[] )
   const char * default_output_filename = "";
   const char ** filenames = 0;
   int num_filenames = 0;
-  int infd = -1;
   enum Mode program_mode = m_compress;
   int argind = 0;
+  int failed_tests = 0;
   int retval = 0;
   int i;
   bool filenames_given = false;
   bool force = false;
   bool ignore_trailing = true;
   bool keep_input_files = false;
+  bool loose_trailing = false;
   bool recompress = false;
   bool stdin_used = false;
   bool to_stdout = false;
   bool zero = false;
   struct Pretty_print pp;
 
+  enum { opt_lt = 256 };
   const struct ap_Option options[] =
     {
-    { '0', "fast",            ap_no  },
-    { '1',  0,                ap_no  },
-    { '2',  0,                ap_no  },
-    { '3',  0,                ap_no  },
-    { '4',  0,                ap_no  },
-    { '5',  0,                ap_no  },
-    { '6',  0,                ap_no  },
-    { '7',  0,                ap_no  },
-    { '8',  0,                ap_no  },
-    { '9', "best",            ap_no  },
-    { 'a', "trailing-error",  ap_no  },
-    { 'b', "member-size",     ap_yes },
-    { 'c', "stdout",          ap_no  },
-    { 'd', "decompress",      ap_no  },
-    { 'f', "force",           ap_no  },
-    { 'F', "recompress",      ap_no  },
-    { 'h', "help",            ap_no  },
-    { 'k', "keep",            ap_no  },
-    { 'l', "list",            ap_no  },
-    { 'm', "match-length",    ap_yes },
-    { 'n', "threads",         ap_yes },
-    { 'o', "output",          ap_yes },
-    { 'q', "quiet",           ap_no  },
-    { 's', "dictionary-size", ap_yes },
-    { 'S', "volume-size",     ap_yes },
-    { 't', "test",            ap_no  },
-    { 'v', "verbose",         ap_no  },
-    { 'V', "version",         ap_no  },
-    {  0 , 0,                 ap_no  } };
+    { '0', "fast",              ap_no  },
+    { '1',  0,                  ap_no  },
+    { '2',  0,                  ap_no  },
+    { '3',  0,                  ap_no  },
+    { '4',  0,                  ap_no  },
+    { '5',  0,                  ap_no  },
+    { '6',  0,                  ap_no  },
+    { '7',  0,                  ap_no  },
+    { '8',  0,                  ap_no  },
+    { '9', "best",              ap_no  },
+    { 'a', "trailing-error",    ap_no  },
+    { 'b', "member-size",       ap_yes },
+    { 'c', "stdout",            ap_no  },
+    { 'd', "decompress",        ap_no  },
+    { 'f', "force",             ap_no  },
+    { 'F', "recompress",        ap_no  },
+    { 'h', "help",              ap_no  },
+    { 'k', "keep",              ap_no  },
+    { 'l', "list",              ap_no  },
+    { 'm', "match-length",      ap_yes },
+    { 'n', "threads",           ap_yes },
+    { 'o', "output",            ap_yes },
+    { 'q', "quiet",             ap_no  },
+    { 's', "dictionary-size",   ap_yes },
+    { 'S', "volume-size",       ap_yes },
+    { 't', "test",              ap_no  },
+    { 'v', "verbose",           ap_no  },
+    { 'V', "version",           ap_no  },
+    { opt_lt, "loose-trailing", ap_no  },
+    {  0 , 0,                   ap_no  } };
 
   struct Arg_parser parser;
 
@@ -865,6 +928,7 @@ int main( const int argc, const char * const argv[] )
       case 't': set_mode( &program_mode, m_test ); break;
       case 'v': if( verbosity < 4 ) ++verbosity; break;
       case 'V': show_version(); return 0;
+      case opt_lt: loose_trailing = true; break;
       default : internal_error( "uncaught option." );
       }
     } /* end process options */
@@ -885,7 +949,7 @@ int main( const int argc, const char * const argv[] )
     }
 
   if( program_mode == m_list )
-    return list_files( filenames, num_filenames, ignore_trailing );
+    return list_files( filenames, num_filenames, ignore_trailing, loose_trailing );
 
   if( program_mode == m_test )
     outfd = -1;
@@ -899,12 +963,14 @@ int main( const int argc, const char * const argv[] )
       ( filenames_given || default_output_filename[0] ) )
     set_signals();
 
-  Pp_init( &pp, filenames, num_filenames, verbosity );
+  Pp_init( &pp, filenames, num_filenames );
 
   output_filename = resize_buffer( output_filename, 1 );
   for( i = 0; i < num_filenames; ++i )
     {
+    unsigned long long cfile_size;
     const char * input_filename = "";
+    int infd;
     int tmp;
     struct stat in_stats;
     const struct stat * in_statsp;
@@ -921,7 +987,7 @@ int main( const int argc, const char * const argv[] )
         else
           {
           if( program_mode == m_compress )
-            set_c_outname( default_output_filename, volume_size > 0 );
+            set_c_outname( default_output_filename, false, volume_size > 0 );
           else
             {
             output_filename = resize_buffer( output_filename,
@@ -931,7 +997,7 @@ int main( const int argc, const char * const argv[] )
           if( !open_outstream( force, true ) )
             {
             if( retval < 1 ) retval = 1;
-            close( infd ); infd = -1;
+            close( infd );
             continue;
             }
           }
@@ -949,12 +1015,12 @@ int main( const int argc, const char * const argv[] )
         else
           {
           if( program_mode == m_compress )
-            set_c_outname( input_filename, volume_size > 0 );
+            set_c_outname( input_filename, true, volume_size > 0 );
           else set_d_outname( input_filename, eindex );
           if( !open_outstream( force, false ) )
             {
             if( retval < 1 ) retval = 1;
-            close( infd ); infd = -1;
+            close( infd );
             continue;
             }
           }
@@ -965,33 +1031,43 @@ int main( const int argc, const char * const argv[] )
     if( !check_tty( pp.name, infd, program_mode ) )
       {
       if( retval < 1 ) retval = 1;
-      if( program_mode == m_test ) { close( infd ); infd = -1; continue; }
+      if( program_mode == m_test ) { close( infd ); continue; }
       cleanup_and_fail( retval );
       }
 
     in_statsp = input_filename[0] ? &in_stats : 0;
+    cfile_size = ( in_statsp && S_ISREG( in_statsp->st_mode ) ) ?
+      ( in_statsp->st_size + 99 ) / 100 : 0;
     if( program_mode == m_compress )
-      tmp = compress( member_size, volume_size, infd, &encoder_options, &pp,
-                      in_statsp, zero );
+      tmp = compress( cfile_size, member_size, volume_size, infd,
+                      &encoder_options, &pp, in_statsp, zero );
     else
-      tmp = decompress( infd, &pp, ignore_trailing, program_mode == m_test );
+      tmp = decompress( cfile_size, infd, &pp, ignore_trailing,
+                        loose_trailing, program_mode == m_test );
     if( tmp > retval ) retval = tmp;
-    if( tmp && program_mode != m_test ) cleanup_and_fail( retval );
+    if( tmp )
+      { if( program_mode != m_test ) cleanup_and_fail( retval );
+        else ++failed_tests; }
 
     if( delete_output_on_interrupt )
       close_and_set_permissions( in_statsp );
     if( input_filename[0] )
       {
-      close( infd ); infd = -1;
-      if( !keep_input_files && !to_stdout && program_mode != m_test )
+      close( infd );
+      if( !keep_input_files && !to_stdout && program_mode != m_test &&
+          ( program_mode != m_compress || volume_size == 0 ) )
         remove( input_filename );
       }
     }
   if( outfd >= 0 && close( outfd ) != 0 )
     {
-    show_error( "Can't close stdout", errno, false );
+    show_error( "Error closing stdout", errno, false );
     if( retval < 1 ) retval = 1;
     }
+  if( failed_tests > 0 && verbosity >= 1 && num_filenames > 1 )
+    fprintf( stderr, "%s: warning: %d %s failed the test.\n",
+             program_name, failed_tests,
+             ( failed_tests == 1 ) ? "file" : "files" );
   free( output_filename );
   free( filenames );
   ap_free( &parser );
diff --git a/testsuite/check.sh b/testsuite/check.sh
index add0722..d12b5de 100755
--- a/testsuite/check.sh
+++ b/testsuite/check.sh
@@ -1,6 +1,6 @@
 #! /bin/sh
 # check script for Clzip - LZMA lossless data compressor
-# Copyright (C) 2010-2017 Antonio Diaz Diaz.
+# Copyright (C) 2010-2018 Antonio Diaz Diaz.
 #
 # This script is free software: you have unlimited permission
 # to copy, distribute and modify it.
@@ -53,6 +53,8 @@ done
 [ $? = 2 ] || test_failed $LINENO
 "${LZIP}" -cdq < in
 [ $? = 2 ] || test_failed $LINENO
+"${LZIP}" -dq -o in < "${in_lz}"
+[ $? = 1 ] || test_failed $LINENO
 # these are for code coverage
 "${LZIP}" -lt "${in_lz}" 2> /dev/null
 [ $? = 1 ] || test_failed $LINENO
@@ -99,6 +101,11 @@ printf "to be overwritten" > copy || framework_failure
 "${LZIP}" -df copy.lz
 { [ $? = 0 ] && [ ! -e copy.lz ] && cmp in copy ; } || test_failed $LINENO
 
+rm -f copy
+cat "${in_lz}" > copy.lz || framework_failure
+"${LZIP}" -d -S100k copy.lz
+{ [ $? = 0 ] && [ ! -e copy.lz ] && cmp in copy ; } || test_failed $LINENO
+
 printf "to be overwritten" > copy || framework_failure
 "${LZIP}" -df -o copy < "${in_lz}" || test_failed $LINENO
 cmp in copy || test_failed $LINENO
@@ -145,7 +152,7 @@ cat "${in_lz}" "${in_lz}" > in2.lz || framework_failure
 "${LZIP}" -cd in2.lz > copy2 || test_failed $LINENO
 cmp in2 copy2 || test_failed $LINENO
 
-"${LZIP}" --output=copy2 < in2 || test_failed $LINENO
+"${LZIP}" --output=copy2.lz < in2 || test_failed $LINENO
 "${LZIP}" -lq copy2.lz || test_failed $LINENO
 "${LZIP}" -t copy2.lz || test_failed $LINENO
 "${LZIP}" -cd copy2.lz > copy2 || test_failed $LINENO
@@ -204,10 +211,14 @@ for i in s4Ki 0 1 2 3 4 5 6 7 8 9 ; do
 done
 
 cat in in in in in in in in > in8 || framework_failure
-"${LZIP}" -1s12 -S100k -o out < in8 || test_failed $LINENO
-"${LZIP}" -t out00001.lz out00002.lz || test_failed $LINENO
-"${LZIP}" -cd out00001.lz out00002.lz | cmp in8 - || test_failed $LINENO
-rm -f out00001.lz
+"${LZIP}" -1s12 -S100k in8 || test_failed $LINENO
+"${LZIP}" -t in800001.lz in800002.lz || test_failed $LINENO
+"${LZIP}" -cd in800001.lz in800002.lz | cmp in8 - || test_failed $LINENO
+rm -f in800001.lz in800002.lz
+"${LZIP}" -1s12 -S100k -o out.lz < in8 || test_failed $LINENO
+"${LZIP}" -t out.lz00001.lz out.lz00002.lz || test_failed $LINENO
+"${LZIP}" -cd out.lz00001.lz out.lz00002.lz | cmp in8 - || test_failed $LINENO
+rm -f out.lz00001.lz out.lz00002.lz
 "${LZIP}" -1ks4Ki -b100000 in8 || test_failed $LINENO
 "${LZIP}" -t in8.lz || test_failed $LINENO
 "${LZIP}" -cd in8.lz | cmp in8 - || test_failed $LINENO
@@ -215,7 +226,15 @@ rm -f in8
 "${LZIP}" -0 -S100k -o out < in8.lz || test_failed $LINENO
 "${LZIP}" -t out00001.lz out00002.lz || test_failed $LINENO
 "${LZIP}" -cd out00001.lz out00002.lz | cmp in8.lz - || test_failed $LINENO
+rm -f out00001.lz
+"${LZIP}" -1 -S100k -o out < in8.lz || test_failed $LINENO
+"${LZIP}" -t out00001.lz out00002.lz || test_failed $LINENO
+"${LZIP}" -cd out00001.lz out00002.lz | cmp in8.lz - || test_failed $LINENO
 rm -f out00001.lz out00002.lz
+"${LZIP}" -0 -F -S100k in8.lz || test_failed $LINENO
+"${LZIP}" -t in8.lz00001.lz in8.lz00002.lz || test_failed $LINENO
+"${LZIP}" -cd in8.lz00001.lz in8.lz00002.lz | cmp in8.lz - || test_failed $LINENO
+rm -f in8.lz00001.lz in8.lz00002.lz
 "${LZIP}" -0kF -b100k in8.lz || test_failed $LINENO
 "${LZIP}" -t in8.lz.lz || test_failed $LINENO
 "${LZIP}" -cd in8.lz.lz | cmp in8.lz - || test_failed $LINENO
@@ -223,6 +242,41 @@ rm -f in8.lz in8.lz.lz
 
 printf "\ntesting bad input..."
 
+headers='LZIp LZiP LZip LzIP LzIp LziP lZIP lZIp lZiP lzIP'
+body='\001\014\000\203\377\373\377\377\300\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000$\000\000\000\000\000\000\000'
+cat "${in_lz}" > in0.lz
+printf "LZIP${body}" >> in0.lz
+if "${LZIP}" -tq in0.lz ; then
+	for header in ${headers} ; do
+		printf "${header}${body}" > in0.lz	# first member
+		"${LZIP}" -lq in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+		"${LZIP}" -tq in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+		"${LZIP}" -lq --loose-trailing in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+		"${LZIP}" -tq --loose-trailing in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+		cat "${in_lz}" > in0.lz
+		printf "${header}${body}" >> in0.lz	# trailing data
+		"${LZIP}" -lq in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+		"${LZIP}" -tq in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+		"${LZIP}" -lq --loose-trailing in0.lz
+		[ $? = 0 ] || test_failed $LINENO ${header}
+		"${LZIP}" -t --loose-trailing in0.lz
+		[ $? = 0 ] || test_failed $LINENO ${header}
+		"${LZIP}" -lq --loose-trailing --trailing-error in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+		"${LZIP}" -tq --loose-trailing --trailing-error in0.lz
+		[ $? = 2 ] || test_failed $LINENO ${header}
+	done
+else
+	printf "\nwarning: skipping header test: 'printf' does not work on your system."
+fi
+rm -f in0.lz
+
 cat "${in_lz}" "${in_lz}" "${in_lz}" > in3.lz || framework_failure
 if dd if=in3.lz of=trunc.lz bs=14752 count=1 2> /dev/null &&
    [ -e trunc.lz ] && cmp in2.lz trunc.lz > /dev/null 2>&1 ; then
@@ -230,7 +284,7 @@ if dd if=in3.lz of=trunc.lz bs=14752 count=1 2> /dev/null &&
 		dd if=in3.lz of=trunc.lz bs=$i count=1 2> /dev/null
 		"${LZIP}" -lq trunc.lz
 		[ $? = 2 ] || test_failed $LINENO $i
-		"${LZIP}" -t trunc.lz 2> /dev/null
+		"${LZIP}" -tq trunc.lz
 		[ $? = 2 ] || test_failed $LINENO $i
 		"${LZIP}" -tq < trunc.lz
 		[ $? = 2 ] || test_failed $LINENO $i
@@ -242,6 +296,7 @@ if dd if=in3.lz of=trunc.lz bs=14752 count=1 2> /dev/null &&
 else
 	printf "\nwarning: skipping truncation test: 'dd' does not work on your system."
 fi
+rm -f in3.lz trunc.lz
 
 cat "${in_lz}" > ingin.lz || framework_failure
 printf "g" >> ingin.lz || framework_failure
@@ -254,6 +309,7 @@ cmp in copy || test_failed $LINENO
 "${LZIP}" -t < ingin.lz || test_failed $LINENO
 "${LZIP}" -d < ingin.lz > copy || test_failed $LINENO
 cmp in copy || test_failed $LINENO
+rm -f ingin.lz
 
 echo
 if [ ${fail} = 0 ] ; then