Reported by Paul Eggert.
* build-aux/useless-if-before-free: Fix comment regarding the second line.
* build-aux/announce-gen: Likewise.
* build-aux/gitlog-to-changelog: Likewise.
* build-aux/prefix-gnulib-mk: Likewise.
* build-aux/update-copyright: Likewise.
* tests/test-update-copyright.sh: Update test program accordingly.
# or execvp() fails with ENOEXEC if it is a script that does not start
# with a #! line. The script interpreter mentioned in the #! line has
# to be /bin/sh, because on GuixSD systems that is the only program that
-# has a fixed file name. The second line is for editing this file in
-# Emacs. The next two lines below are valid code in both sh and perl.
-# When executed by sh, they re-execute the script through the perl
-# program found in $PATH. The '-x' option is essential; without it,
-# perl would re-execute the script through /bin/sh. When executed by
-# perl, the next two lines are a no-op.
+# has a fixed file name. The second line is essential for perl and is
+# also useful for editing this file in Emacs. The next two lines below
+# are valid code in both sh and perl. When executed by sh, they re-execute
+# the script through the perl program found in $PATH. The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh. When executed by perl, the next two lines are a no-op.
eval 'exec perl -wSx "$0" "$@"'
if 0;
# or execvp() fails with ENOEXEC if it is a script that does not start
# with a #! line. The script interpreter mentioned in the #! line has
# to be /bin/sh, because on GuixSD systems that is the only program that
-# has a fixed file name. The second line is for editing this file in
-# Emacs. The next two lines below are valid code in both sh and perl.
-# When executed by sh, they re-execute the script through the perl
-# program found in $PATH. The '-x' option is essential; without it,
-# perl would re-execute the script through /bin/sh. When executed by
-# perl, the next two lines are a no-op.
+# has a fixed file name. The second line is essential for perl and is
+# also useful for editing this file in Emacs. The next two lines below
+# are valid code in both sh and perl. When executed by sh, they re-execute
+# the script through the perl program found in $PATH. The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh. When executed by perl, the next two lines are a no-op.
eval 'exec perl -wSx "$0" "$@"'
if 0;
# or execvp() fails with ENOEXEC if it is a script that does not start
# with a #! line. The script interpreter mentioned in the #! line has
# to be /bin/sh, because on GuixSD systems that is the only program that
-# has a fixed file name. The second line is for editing this file in
-# Emacs. The next two lines below are valid code in both sh and perl.
-# When executed by sh, they re-execute the script through the perl
-# program found in $PATH. The '-x' option is essential; without it,
-# perl would re-execute the script through /bin/sh. When executed by
-# perl, the next two lines are a no-op.
+# has a fixed file name. The second line is essential for perl and is
+# also useful for editing this file in Emacs. The next two lines below
+# are valid code in both sh and perl. When executed by sh, they re-execute
+# the script through the perl program found in $PATH. The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh. When executed by perl, the next two lines are a no-op.
eval 'exec perl -wSx "$0" "$@"'
if 0;
# or execvp() fails with ENOEXEC if it is a script that does not start
# with a #! line. The script interpreter mentioned in the #! line has
# to be /bin/sh, because on GuixSD systems that is the only program that
-# has a fixed file name. The second line is for editing this file in
-# Emacs. The next two lines below are valid code in both sh and perl.
-# When executed by sh, they re-execute the script through the perl
-# program found in $PATH. The '-x' option is essential; without it,
-# perl would re-execute the script through /bin/sh. When executed by
-# perl, the next two lines are a no-op.
+# has a fixed file name. The second line is essential for perl and is
+# also useful for editing this file in Emacs. The next two lines below
+# are valid code in both sh and perl. When executed by sh, they re-execute
+# the script through the perl program found in $PATH. The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh. When executed by perl, the next two lines are a no-op.
eval 'exec perl -wSx "$0" "$@"'
if 0;
# or execvp() fails with ENOEXEC if it is a script that does not start
# with a #! line. The script interpreter mentioned in the #! line has
# to be /bin/sh, because on GuixSD systems that is the only program that
-# has a fixed file name. The second line is for editing this file in
-# Emacs. The next two lines below are valid code in both sh and perl.
-# When executed by sh, they re-execute the script through the perl
-# program found in $PATH. The '-x' option is essential; without it,
-# perl would re-execute the script through /bin/sh. When executed by
-# perl, the next two lines are a no-op.
+# has a fixed file name. The second line is essential for perl and is
+# also useful for editing this file in Emacs. The next two lines below
+# are valid code in both sh and perl. When executed by sh, they re-execute
+# the script through the perl program found in $PATH. The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh. When executed by perl, the next two lines are a no-op.
eval 'exec perl -wSx "$0" "$@"'
if 0;
# or execvp() fails with ENOEXEC if it is a script that does not start
# with a #! line. The script interpreter mentioned in the #! line has
# to be /bin/sh, because on GuixSD systems that is the only program that
-# has a fixed file name. The second line is for editing this file in
-# Emacs. The next two lines below are valid code in both sh and perl.
-# When executed by sh, they re-execute the script through the perl
-# program found in $PATH. The '-x' option is essential; without it,
-# perl would re-execute the script through /bin/sh. When executed by
-# perl, the next two lines are a no-op.
+# has a fixed file name. The second line is essential for perl and is
+# also useful for editing this file in Emacs. The next two lines below
+# are valid code in both sh and perl. When executed by sh, they re-execute
+# the script through the perl program found in $PATH. The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh. When executed by perl, the next two lines are a no-op.
eval 'exec perl -wSx "$0" "$@"'
if 0;