Merging upstream version 1.6.

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

8 files changed, 86 insertions, 71 deletions

diff --git a/doc/zcat.1 b/doc/zcat.1
index b67aa40..9a76208 100644
--- a/doc/zcat.1
+++ b/doc/zcat.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH ZCAT "1" "May 2016" "zcat (zutils) 1.5" "User Commands"
+.TH ZCAT "1" "April 2017" "zcat (zutils) 1.6" "User Commands"
 .SH NAME
 zcat \- decompress and concatenate files to standard output
 .SH SYNOPSIS
@@ -11,7 +11,7 @@ compressed, its decompressed content is used. If a given file does not
 exist, and its name does not end with one of the known extensions, zcat
 tries the compressed file names corresponding to the supported formats.
 .PP
-If no files are specified, or if a file is specified as '\-', data is
+If no files are specified, or if a file is specified as '\-', data are
 read from standard input, decompressed if needed, and sent to standard
 output. Data read from standard input must be of the same type; all
 uncompressed or all in the same compression format.
@@ -88,7 +88,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2016 Antonio Diaz Diaz.
+Copyright \(co 2017 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/zcmp.1 b/doc/zcmp.1
index 33f725e..c9583f8 100644
--- a/doc/zcmp.1
+++ b/doc/zcmp.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH ZCMP "1" "May 2016" "zcmp (zutils) 1.5" "User Commands"
+.TH ZCMP "1" "April 2017" "zcmp (zutils) 1.6" "User Commands"
 .SH NAME
 zcmp \- decompress and compare two files byte by byte
 .SH SYNOPSIS
@@ -14,17 +14,17 @@ fly; no temporary files are created.
 .PP
 The supported formats are bzip2, gzip, lzip and xz.
 .PP
-Compares <file1> to <file2>. If <file2> is omitted zcmp tries the
+Zcmp compares file1 to file2. If file2 is omitted zcmp tries the
 following:
 .IP
-1. If <file1> is compressed, compares its decompressed contents with
-the corresponding uncompressed file (the name of <file1> with the
+1. If file1 is compressed, compares its decompressed contents with
+the corresponding uncompressed file (the name of file1 with the
 extension removed).
 .IP
-2. If <file1> is uncompressed, compares it with the decompressed
-contents of <file1>.[lz|bz2|gz|xz] (the first one that is found).
+2. If file1 is uncompressed, compares it with the decompressed
+contents of file1.[lz|bz2|gz|xz] (the first one that is found).
 .IP
-3. If no suitable file is found, compares <file1> with data read from
+3. If no suitable file is found, compares file1 with data read from
 standard input.
 .PP
 Exit status is 0 if inputs are identical, 1 if different, 2 if trouble.
@@ -39,7 +39,7 @@ output version information and exit
 \fB\-b\fR, \fB\-\-print\-bytes\fR
 print differing bytes
 .TP
-\fB\-i\fR, \fB\-\-ignore\-initial=\fR<n>[,<n2>]
+\fB\-i\fR, \fB\-\-ignore\-initial=\fR<n>[:<n2>]
 ignore differences in the first <n> bytes
 .TP
 \fB\-l\fR, \fB\-\-list\fR
@@ -85,7 +85,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2016 Antonio Diaz Diaz.
+Copyright \(co 2017 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/zdiff.1 b/doc/zdiff.1
index 3e1d607..f803ee8 100644
--- a/doc/zdiff.1
+++ b/doc/zdiff.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH ZDIFF "1" "May 2016" "zdiff (zutils) 1.5" "User Commands"
+.TH ZDIFF "1" "April 2017" "zdiff (zutils) 1.6" "User Commands"
 .SH NAME
 zdiff \- decompress and compare two files line by line
 .SH SYNOPSIS
@@ -14,17 +14,17 @@ temporary filenames instead of those specified.
 .PP
 The supported formats are bzip2, gzip, lzip and xz.
 .PP
-Compares <file1> to <file2>. If <file2> is omitted zdiff tries the
+Zdiff compares file1 to file2. If file2 is omitted zdiff tries the
 following:
 .IP
-1. If <file1> is compressed, compares its decompressed contents with
-the corresponding uncompressed file (the name of <file1> with the
+1. If file1 is compressed, compares its decompressed contents with
+the corresponding uncompressed file (the name of file1 with the
 extension removed).
 .IP
-2. If <file1> is uncompressed, compares it with the decompressed
-contents of <file1>.[lz|bz2|gz|xz] (the first one that is found).
+2. If file1 is uncompressed, compares it with the decompressed
+contents of file1.[lz|bz2|gz|xz] (the first one that is found).
 .IP
-3. If no suitable file is found, compares <file1> with data read from
+3. If no suitable file is found, compares file1 with data read from
 standard input.
 .PP
 Exit status is 0 if inputs are identical, 1 if different, 2 if trouble.
@@ -109,7 +109,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2016 Antonio Diaz Diaz.
+Copyright \(co 2017 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/zgrep.1 b/doc/zgrep.1
index 67d8277..571d410 100644
--- a/doc/zgrep.1
+++ b/doc/zgrep.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH ZGREP "1" "May 2016" "zgrep (zutils) 1.5" "User Commands"
+.TH ZGREP "1" "April 2017" "zgrep (zutils) 1.6" "User Commands"
 .SH NAME
 zgrep \- search compressed files for a regular expression
 .SH SYNOPSIS
@@ -13,7 +13,7 @@ does not exist, and its name does not end with one of the known
 extensions, zgrep tries the compressed file names corresponding to the
 supported formats.
 .PP
-If no files are specified, or if a file is specified as '\-', data is
+If no files are specified, or if a file is specified as '\-', data are
 read from standard input, decompressed if needed, and fed to grep. Data
 read from standard input must be of the same type; all uncompressed or
 all in the same compression format.
@@ -135,7 +135,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2016 Antonio Diaz Diaz.
+Copyright \(co 2017 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/ztest.1 b/doc/ztest.1
index 3311667..252489b 100644
--- a/doc/ztest.1
+++ b/doc/ztest.1
@@ -1,7 +1,7 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH ZTEST "1" "May 2016" "ztest (zutils) 1.5" "User Commands"
+.TH ZTEST "1" "April 2017" "ztest (zutils) 1.6" "User Commands"
 .SH NAME
-ztest \- verify integrity of compressed files
+ztest \- verify the integrity of compressed files
 .SH SYNOPSIS
 .B ztest
 [\fI\,options\/\fR] [\fI\,files\/\fR]
@@ -14,8 +14,12 @@ compression format.
 .PP
 The supported formats are bzip2, gzip, lzip and xz.
 .PP
-Note that some xz files lack integrity information, and therefore can't
-be verified as reliably as the other formats can.
+Note that error detection in the xz format is broken. First, some xz
+files lack integrity information. Second, not all xz decompressors can
+verify the integrity of all xz files. Third, section 2.1.1.2 'Stream
+Flags' of the xz format specification allows xz decompressors to produce
+garbage output without issuing any warning. Therefore, xz files can't
+always be verified as reliably as files in the other formats can.
 .PP
 Exit status is 0 if all compressed files verify OK, 1 if environmental
 problems (file not found, invalid flags, I/O errors, etc), 2 if any
@@ -62,7 +66,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2016 Antonio Diaz Diaz.
+Copyright \(co 2017 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/zupdate.1 b/doc/zupdate.1
index 059867e..6894418 100644
--- a/doc/zupdate.1
+++ b/doc/zupdate.1
@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH ZUPDATE "1" "May 2016" "zupdate (zutils) 1.5" "User Commands"
+.TH ZUPDATE "1" "April 2017" "zupdate (zutils) 1.6" "User Commands"
 .SH NAME
 zupdate \- recompress bzip2, gzip, xz files to lzip format
 .SH SYNOPSIS
@@ -76,7 +76,7 @@ Report bugs to zutils\-bug@nongnu.org
 .br
 Zutils home page: http://www.nongnu.org/zutils/zutils.html
 .SH COPYRIGHT
-Copyright \(co 2016 Antonio Diaz Diaz.
+Copyright \(co 2017 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/zutils.info b/doc/zutils.info
index b753ec0..98ddf49 100644
--- a/doc/zutils.info
+++ b/doc/zutils.info
@@ -12,7 +12,7 @@ File: zutils.info,  Node: Top,  Next: Introduction,  Up: (dir)
 Zutils Manual
 *************
 
-This manual is for Zutils (version 1.5, 15 May 2016).
+This manual is for Zutils (version 1.6, 5 April 2017).
 
 * Menu:
 
@@ -23,13 +23,13 @@ This manual is for Zutils (version 1.5, 15 May 2016).
 * Zcmp::                Comparing compressed files byte by byte
 * Zdiff::               Comparing compressed files line by line
 * Zgrep::               Searching inside compressed files
-* Ztest::               Testing integrity of compressed files
+* Ztest::               Testing the integrity of compressed files
 * Zupdate::             Recompressing files to lzip format
 * Problems::            Reporting bugs
 * Concept index::       Index of concepts
 
 
-   Copyright (C) 2009-2016 Antonio Diaz Diaz.
+   Copyright (C) 2009-2017 Antonio Diaz Diaz.
 
    This manual is free documentation: you have unlimited permission to
 copy, distribute and modify it.
@@ -64,9 +64,9 @@ which makes them safe to use with zutils. Gzip and xz may return
 ambiguous warning values, making them less reliable back ends for
 zutils.  *Note compressor-requirements::.
 
-   FORMAT NOTE: The '--format' option allows the processing of a subset
-of formats in search and recursive modes:
-'zgrep foo -r --format=bz2,lz somedir'.
+   FORMAT NOTE 1: The '--format' option allows the processing of a
+subset of formats in recursive mode and when trying compressed file
+names: 'zgrep foo -r --format=bz2,lz somedir somefile.tar'.
 
    FORMAT NOTE 2: If the '--force-format' option is given, the files
 are passed to the corresponding decompressor without verifying their
@@ -75,7 +75,7 @@ with gzip: 'zcmp --force-format=gz file.Z file.lz'.
 
    LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may
 never have been compressed. Decompressed is used to refer to data which
-has undergone the process of decompression.
+have undergone the process of decompression.
 
 
    Numbers given as arguments to options (positions, sizes) may be
@@ -192,10 +192,10 @@ compressed, its decompressed content is used. If a given file does not
 exist, and its name does not end with one of the known extensions, zcat
 tries the compressed file names corresponding to the supported formats.
 
-   If no files are specified, or if a file is specified as '-', data is
-read from standard input, decompressed if needed, and sent to standard
-output. Data read from standard input must be of the same type; all
-uncompressed or all in the same compression format.
+   If no files are specified, or if a file is specified as '-', data
+are read from standard input, decompressed if needed, and sent to
+standard output. Data read from standard input must be of the same type;
+all uncompressed or all in the same compression format.
 
    The format for running zcat is:
 
@@ -307,7 +307,7 @@ differences were found, and 2 means trouble.
 '--ignore-initial=SIZE'
      Ignore any differences in the first SIZE bytes of the input files.
      Treat files with fewer than SIZE bytes as if they were empty. If
-     SIZE is in the form 'SIZE1,SIZE2', ignore the first SIZE1 bytes of
+     SIZE is in the form 'SIZE1:SIZE2', ignore the first SIZE1 bytes of
      the first input file and the first SIZE2 bytes of the second input
      file.
 
@@ -460,8 +460,8 @@ does not exist, and its name does not end with one of the known
 extensions, zgrep tries the compressed file names corresponding to the
 supported formats.
 
-   If no files are specified, or if a file is specified as '-', data is
-read from standard input, decompressed if needed, and fed to grep.
+   If no files are specified, or if a file is specified as '-', data
+are read from standard input, decompressed if needed, and fed to grep.
 Data read from standard input must be of the same type; all uncompressed
 or all in the same compression format.
 
@@ -602,8 +602,12 @@ is specified as '-', the integrity of compressed data read from
 standard input is verified. Data read from standard input must be all in
 the same compression format.
 
-   Note that some xz files lack integrity information, and therefore
-can't be verified as reliably as the other formats can.
+   Note that error detection in the xz format is broken. First, some xz
+files lack integrity information. Second, not all xz decompressors can
+verify the integrity of all xz files. Third, section 2.1.1.2 'Stream
+Flags' of the xz format specification allows xz decompressors to
+produce garbage output without issuing any warning. Therefore, xz files
+can't always be verified as reliably as files in the other formats can.
 
    The format for running ztest is:
 
@@ -761,18 +765,18 @@ Concept index
 
 Tag Table:
 Node: Top222
-Node: Introduction1142
-Node: Common options3726
-Ref: compressor-requirements5484
-Node: The zutilsrc file5856
-Node: Zcat6781
-Node: Zcmp8834
-Node: Zdiff11293
-Node: Zgrep13933
-Node: Ztest17271
-Node: Zupdate18809
-Node: Problems21681
-Node: Concept index22215
+Node: Introduction1147
+Node: Common options3773
+Ref: compressor-requirements5531
+Node: The zutilsrc file5903
+Node: Zcat6828
+Node: Zcmp8882
+Node: Zdiff11341
+Node: Zgrep13981
+Node: Ztest17320
+Node: Zupdate19154
+Node: Problems22026
+Node: Concept index22560
 
 End Tag Table
 
diff --git a/doc/zutils.texi b/doc/zutils.texi
index 34c15b4..ea9fb2d 100644
--- a/doc/zutils.texi
+++ b/doc/zutils.texi
@@ -6,8 +6,8 @@
 @finalout
 @c %**end of header
 
-@set UPDATED 15 May 2016
-@set VERSION 1.5
+@set UPDATED 5 April 2017
+@set VERSION 1.6
 
 @dircategory Data Compression
 @direntry
@@ -42,14 +42,14 @@ This manual is for Zutils (version @value{VERSION}, @value{UPDATED}).
 * Zcmp::                Comparing compressed files byte by byte
 * Zdiff::               Comparing compressed files line by line
 * Zgrep::               Searching inside compressed files
-* Ztest::               Testing integrity of compressed files
+* Ztest::               Testing the integrity of compressed files
 * Zupdate::             Recompressing files to lzip format
 * Problems::            Reporting bugs
 * Concept index::       Index of concepts
 @end menu
 
 @sp 1
-Copyright @copyright{} 2009-2016 Antonio Diaz Diaz.
+Copyright @copyright{} 2009-2017 Antonio Diaz Diaz.
 
 This manual is free documentation: you have unlimited permission
 to copy, distribute and modify it.
@@ -84,9 +84,9 @@ makes them safe to use with zutils. Gzip and xz may return ambiguous
 warning values, making them less reliable back ends for zutils.
 @xref{compressor-requirements}.
 
-FORMAT NOTE: The @samp{--format} option allows the processing of a
-subset of formats in search and recursive modes:
-@w{@samp{zgrep foo -r --format=bz2,lz somedir}}.
+FORMAT NOTE 1: The @samp{--format} option allows the processing of a
+subset of formats in recursive mode and when trying compressed file
+names: @w{@samp{zgrep foo -r --format=bz2,lz somedir somefile.tar}}.
 
 FORMAT NOTE 2: If the @samp{--force-format} option is given, the files
 are passed to the corresponding decompressor without verifying their
@@ -94,7 +94,7 @@ format, allowing for example the processing of compress'd (.Z) files
 with gzip: @w{@samp{zcmp --force-format=gz file.Z file.lz}}.
 
 LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may never
-have been compressed. Decompressed is used to refer to data which has
+have been compressed. Decompressed is used to refer to data which have
 undergone the process of decompression.
 
 @sp 1
@@ -224,7 +224,7 @@ exist, and its name does not end with one of the known extensions, zcat
 tries the compressed file names corresponding to the supported formats.
 
 If no files are specified, or if a file is specified as @samp{-}, data
-is read from standard input, decompressed if needed, and sent to
+are read from standard input, decompressed if needed, and sent to
 standard output. Data read from standard input must be of the same type;
 all uncompressed or all in the same compression format.
 
@@ -349,7 +349,7 @@ for "meta").
 @itemx --ignore-initial=@var{size}
 Ignore any differences in the first @var{size} bytes of the input files.
 Treat files with fewer than @var{size} bytes as if they were empty. If
-@var{size} is in the form @samp{@var{size1},@var{size2}}, ignore the
+@var{size} is in the form @samp{@var{size1}:@var{size2}}, ignore the
 first @var{size1} bytes of the first input file and the first
 @var{size2} bytes of the second input file.
 
@@ -511,7 +511,7 @@ extensions, zgrep tries the compressed file names corresponding to the
 supported formats.
 
 If no files are specified, or if a file is specified as @samp{-}, data
-is read from standard input, decompressed if needed, and fed to grep.
+are read from standard input, decompressed if needed, and fed to grep.
 Data read from standard input must be of the same type; all uncompressed
 or all in the same compression format.
 
@@ -657,8 +657,15 @@ is specified as @samp{-}, the integrity of compressed data read from
 standard input is verified. Data read from standard input must be all in
 the same compression format.
 
-Note that some xz files lack integrity information, and therefore can't
-be verified as reliably as the other formats can.
+Note that error detection in the xz format is broken. First, some xz
+files lack integrity information. Second, not all xz decompressors can
+@uref{http://www.nongnu.org/lzip/xz_inadequate.html#fragmented,,verify the integrity}
+of all xz files. Third, section 2.1.1.2 'Stream Flags' of the
+@uref{http://tukaani.org/xz/xz-file-format.txt,,xz format specification}
+allows xz decompressors to produce garbage output without issuing any
+warning. Therefore, xz files can't always be verified as reliably as
+files in the other formats can.
+@c We can only hope that xz is soon abandoned.
 
 The format for running ztest is: