maint: update copyright year number ranges

Run 'make update-copyright'.

* lib/regexprops.c (copying): Update the year number manually.
The format of the copyright year number range in Texinfo files is
"YEAR1--YEAR2" now, i.e., with 2x '-'.
* tests/sample-test: Likewise, here to avoid starting a year number range.
* All other files: Update copyright years via the above make run.

30 files changed, 32 insertions, 31 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 1c4440fa..bdebccdf 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,6 +1,6 @@
 ## Process this file with automake to produce Makefile.in.
 
-## Copyright (C) 1996-2020 Free Software Foundation, Inc.
+## Copyright (C) 1996-2021 Free Software Foundation, Inc.
 
 ## 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/lib/bugreports.c b/lib/bugreports.c
index 4d226e3a..15b56771 100644
--- a/lib/bugreports.c
+++ b/lib/bugreports.c
@@ -1,5 +1,5 @@
 /* bugreports.h -- explain how to report bugs
-   Copyright (C) 2016-2020 Free Software Foundation, Inc.
+   Copyright (C) 2016-2021 Free Software Foundation, Inc.
 
    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/lib/bugreports.h b/lib/bugreports.h
index 5dda77cc..2aa35c2b 100644
--- a/lib/bugreports.h
+++ b/lib/bugreports.h
@@ -1,5 +1,5 @@
 /* bugreports.h -- explain how to report bugs
-   Copyright (C) 2016-2020 Free Software Foundation, Inc.
+   Copyright (C) 2016-2021 Free Software Foundation, Inc.
 
    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/lib/buildcmd.c b/lib/buildcmd.c
index 17f364fe..712940a8 100644
--- a/lib/buildcmd.c
+++ b/lib/buildcmd.c
@@ -1,5 +1,5 @@
 /* buildcmd.c -- build command lines from a list of arguments.
-   Copyright (C) 1990-2020 Free Software Foundation, Inc.
+   Copyright (C) 1990-2021 Free Software Foundation, Inc.
 
    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/lib/buildcmd.h b/lib/buildcmd.h
index 3763a9b1..824418b7 100644
--- a/lib/buildcmd.h
+++ b/lib/buildcmd.h
@@ -1,5 +1,5 @@
 /* buildcmd.[ch] -- build command lines from a stream of arguments
-   Copyright (C) 2005-2020 Free Software Foundation, Inc.
+   Copyright (C) 2005-2021 Free Software Foundation, Inc.
 
    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/lib/check-regexprops.sh b/lib/check-regexprops.sh
index d1701381..e2f2b2c7 100755
--- a/lib/check-regexprops.sh
+++ b/lib/check-regexprops.sh
@@ -1,7 +1,7 @@
 #! /bin/sh
 # Generate regexprops.texi and compare it against the checked-in version.
 #
-# Copyright (C) 2009-2020 Free Software Foundation, Inc.
+# Copyright (C) 2009-2021 Free Software Foundation, Inc.
 #
 # 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/lib/die.h b/lib/die.h
index 9ec07f4b..70e50a64 100644
--- a/lib/die.h
+++ b/lib/die.h
@@ -1,5 +1,5 @@
 /* Report an error and exit.
-   Copyright (C) 2017-2020 Free Software Foundation, Inc.
+   Copyright (C) 2017-2021 Free Software Foundation, Inc.
 
    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/lib/dircallback.c b/lib/dircallback.c
index e1204565..ffaefec8 100644
--- a/lib/dircallback.c
+++ b/lib/dircallback.c
@@ -1,5 +1,5 @@
 /* listfile.c -- run a function in a specific directory
-   Copyright (C) 2007-2020 Free Software Foundation, Inc.
+   Copyright (C) 2007-2021 Free Software Foundation, Inc.
 
    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/lib/dircallback.h b/lib/dircallback.h
index c39c2218..a1f9f939 100644
--- a/lib/dircallback.h
+++ b/lib/dircallback.h
@@ -1,5 +1,5 @@
 /* listfile.h -- display a long listing of a file
-   Copyright (C) 2007-2020 Free Software Foundation, Inc.
+   Copyright (C) 2007-2021 Free Software Foundation, Inc.
 
    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/lib/extendbuf.c b/lib/extendbuf.c
index 0c02aecb..d38a80e1 100644
--- a/lib/extendbuf.c
+++ b/lib/extendbuf.c
@@ -1,6 +1,6 @@
 /* extendbuf.c -- manage a dynamically-allocated buffer
 
-   Copyright (C) 2004-2020 Free Software Foundation, Inc.
+   Copyright (C) 2004-2021 Free Software Foundation, Inc.
 
    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/lib/extendbuf.h b/lib/extendbuf.h
index e5d7a136..8a74d4f2 100644
--- a/lib/extendbuf.h
+++ b/lib/extendbuf.h
@@ -1,6 +1,6 @@
 /* extendbuf.h -- Manage a dynamically-alloicated buffer
 
-   Copyright (C) 2004-2020 Free Software Foundation, Inc.
+   Copyright (C) 2004-2021 Free Software Foundation, Inc.
 
    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/lib/fdleak.c b/lib/fdleak.c
index 7509b8f5..ce1ad7db 100644
--- a/lib/fdleak.c
+++ b/lib/fdleak.c
@@ -1,5 +1,5 @@
 /* fdleak.c -- detect file descriptor leaks
-   Copyright (C) 2010-2020 Free Software Foundation, Inc.
+   Copyright (C) 2010-2021 Free Software Foundation, Inc.
 
    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/lib/fdleak.h b/lib/fdleak.h
index d427a40f..fdb20ca3 100644
--- a/lib/fdleak.h
+++ b/lib/fdleak.h
@@ -1,5 +1,5 @@
 /* fdleak.h -- detect file descriptor leaks
-   Copyright (C) 2010-2020 Free Software Foundation, Inc.
+   Copyright (C) 2010-2021 Free Software Foundation, Inc.
 
    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/lib/findutils-version.c b/lib/findutils-version.c
index 6deeacdb..ae47a8f6 100644
--- a/lib/findutils-version.c
+++ b/lib/findutils-version.c
@@ -1,5 +1,5 @@
 /* findutils-version.c -- show version information for findutils
-   Copyright (C) 2007-2020 Free Software Foundation, Inc.
+   Copyright (C) 2007-2021 Free Software Foundation, Inc.
 
    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/lib/findutils-version.h b/lib/findutils-version.h
index 20660074..5c7b44d2 100644
--- a/lib/findutils-version.h
+++ b/lib/findutils-version.h
@@ -1,5 +1,5 @@
 /* findutils-version.h -- show version information for findutils
-   Copyright (C) 2007-2020 Free Software Foundation, Inc.
+   Copyright (C) 2007-2021 Free Software Foundation, Inc.
 
    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/lib/listfile.c b/lib/listfile.c
index 49382a96..14c783ab 100644
--- a/lib/listfile.c
+++ b/lib/listfile.c
@@ -1,5 +1,5 @@
 /* listfile.c -- display a long listing of a file
-   Copyright (C) 1991-2020 Free Software Foundation, Inc.
+   Copyright (C) 1991-2021 Free Software Foundation, Inc.
 
    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/lib/listfile.h b/lib/listfile.h
index 4557e1e6..310435d8 100644
--- a/lib/listfile.h
+++ b/lib/listfile.h
@@ -1,5 +1,5 @@
 /* listfile.h -- display a long listing of a file
-   Copyright (C) 1991-2020 Free Software Foundation, Inc.
+   Copyright (C) 1991-2021 Free Software Foundation, Inc.
 
    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/lib/printquoted.c b/lib/printquoted.c
index d850063a..a03ddbb5 100644
--- a/lib/printquoted.c
+++ b/lib/printquoted.c
@@ -1,6 +1,6 @@
 /* printquoted.c -- print a specified string with any necessary quoting.
 
-   Copyright (C) 1990-2020 Free Software Foundation, Inc.
+   Copyright (C) 1990-2021 Free Software Foundation, Inc.
 
    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/lib/printquoted.h b/lib/printquoted.h
index f56019b9..6877cc99 100644
--- a/lib/printquoted.h
+++ b/lib/printquoted.h
@@ -1,6 +1,6 @@
 /* Print a string, appropriately quoted.
 
-   Copyright (C) 1997-2020 Free Software Foundation, Inc.
+   Copyright (C) 1997-2021 Free Software Foundation, Inc.
 
    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/lib/qmark.c b/lib/qmark.c
index a612e01e..53113f0e 100644
--- a/lib/qmark.c
+++ b/lib/qmark.c
@@ -1,6 +1,6 @@
 /* qmark.c -- quote 'dangerous' filenames
    Derived from coreutils' ls.c.
-   Copyright (C) 1985-2020 Free Software Foundation, Inc.
+   Copyright (C) 1985-2021 Free Software Foundation, Inc.
 
    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/lib/regexprops.c b/lib/regexprops.c
index 81225f4d..8466674f 100644
--- a/lib/regexprops.c
+++ b/lib/regexprops.c
@@ -1,7 +1,7 @@
 /* regexprops.c -- document the properties of the regular expressions
    understood by gnulib.
 
-   Copyright (C) 2005-2020 Free Software Foundation, Inc.
+   Copyright (C) 2005-2021 Free Software Foundation, Inc.
 
    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
@@ -453,7 +453,8 @@ copying (void)
 {
   static const char *copy_para[]=
     {
-      "Copyright (C) 1994-2020 Free Software Foundation, Inc."
+      /* The copyright year number range is with "--" in Texinfo files.  */
+      "Copyright (C) 1994--2021 Free Software Foundation, Inc."
       ,""
       ,"Permission is granted to copy, distribute and/or modify this document"
       ,"under the terms of the GNU Free Documentation License, Version 1.3 or"
diff --git a/lib/regextype.c b/lib/regextype.c
index 25c6c1ca..b5a0a868 100644
--- a/lib/regextype.c
+++ b/lib/regextype.c
@@ -2,7 +2,7 @@
 /* regextype.c -- Decode the name of a regular expression syntax into am
                   option name.
 
-   Copyright (C) 2005-2020 Free Software Foundation, Inc.
+   Copyright (C) 2005-2021 Free Software Foundation, Inc.
 
    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/lib/regextype.h b/lib/regextype.h
index 951cbc42..2bb9ab59 100644
--- a/lib/regextype.h
+++ b/lib/regextype.h
@@ -1,6 +1,6 @@
 /* regextype.h -- Decode the name of a regular expression syntax.
 
-   Copyright (C) 2005-2020 Free Software Foundation, Inc.
+   Copyright (C) 2005-2021 Free Software Foundation, Inc.
 
    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/lib/safe-atoi.c b/lib/safe-atoi.c
index 8a3964da..6b9394eb 100644
--- a/lib/safe-atoi.c
+++ b/lib/safe-atoi.c
@@ -1,5 +1,5 @@
 /* safe-atoi.c -- checked string-to-int conversion.
-   Copyright (C) 2007-2020 Free Software Foundation, Inc.
+   Copyright (C) 2007-2021 Free Software Foundation, Inc.
 
    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/lib/safe-atoi.h b/lib/safe-atoi.h
index a1e7e5cc..78115cec 100644
--- a/lib/safe-atoi.h
+++ b/lib/safe-atoi.h
@@ -1,5 +1,5 @@
 /* safe-atoi.h -- checked string-to-int conversion.
-   Copyright (C) 2010-2020 Free Software Foundation, Inc.
+   Copyright (C) 2010-2021 Free Software Foundation, Inc.
 
    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/lib/splitstring.c b/lib/splitstring.c
index 70c586ae..99d5c95e 100644
--- a/lib/splitstring.c
+++ b/lib/splitstring.c
@@ -1,5 +1,5 @@
 /* splitstring.c -- split a const string into fields.
-   Copyright (C) 2011-2020 Free Software Foundation, Inc.
+   Copyright (C) 2011-2021 Free Software Foundation, Inc.
 
    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/lib/splitstring.h b/lib/splitstring.h
index 90bb3ac8..8bde463f 100644
--- a/lib/splitstring.h
+++ b/lib/splitstring.h
@@ -1,5 +1,5 @@
 /* splitstring.h -- split a const string into fields.
-   Copyright (C) 2011-2020 Free Software Foundation, Inc.
+   Copyright (C) 2011-2021 Free Software Foundation, Inc.
 
    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/lib/system.h b/lib/system.h
index 07b2302d..c0f5ccf5 100644
--- a/lib/system.h
+++ b/lib/system.h
@@ -1,6 +1,6 @@
 /* system.h -- system-dependent definitions for findutils
 
-   Copyright (C) 2017-2020 Free Software Foundation, Inc.
+   Copyright (C) 2017-2021 Free Software Foundation, Inc.
 
    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/lib/test_splitstring.c b/lib/test_splitstring.c
index 6866eb07..80e4bacc 100644
--- a/lib/test_splitstring.c
+++ b/lib/test_splitstring.c
@@ -1,5 +1,5 @@
 /* test_splitstring.c -- unit test for splitstring()
-   Copyright (C) 2011-2020 Free Software Foundation, Inc.
+   Copyright (C) 2011-2021 Free Software Foundation, Inc.
 
    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/lib/unused-result.h b/lib/unused-result.h
index 4bc3b6eb..4eaac963 100644
--- a/lib/unused-result.h
+++ b/lib/unused-result.h
@@ -1,5 +1,5 @@
 /* unused-result.h -- macros for ensuring callers don't ignore return values
-   Copyright (C) 2010-2020 Free Software Foundation, Inc.
+   Copyright (C) 2010-2021 Free Software Foundation, Inc.
 
    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