head,tail: quote name in file headers appropriately

* src/tail.c (write_header): Use quotef() to quote
file names when needed.
* src/head.c (write_header): Likewise.
* tests/head/quote-headers.sh: Add a new test.
* tests/tail/quote-headers.sh: Add a new test.
* tests/local.mk: Reference the new test.
Reported by Michał Majchrowicz.

diff --git a/NEWS b/NEWS
index d4963b2758ab60f44535ac294c8ae03affce5869..4dad878b039b317b5bdfb8afa637be461c3efbc5 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,9 @@ GNU coreutils NEWS                                    -*- outline -*-
   mistakenly exit with a nonzero status.
   [This bug was present in "the beginning".]
 
+  'head' and 'tail' now quote names in file headers when needed.
+  [This bug was present in "the beginning".]
+
   'pinky -l' no longer no longer prints output in the incorrect order when
   standard output is fully buffered, e.g., when redirected to a file.
   [bug introduced in coreutils-9.10]

diff --git a/src/head.c b/src/head.c
index e6596ecbe132e7f781c73a4f98dda2e0e75bcbf8..96c967d8cd0084f3fcb0654988fa470412f214ea 100644 (file)
--- a/src/head.c
+++ b/src/head.c
@@ -180,7 +180,7 @@ write_header (char const *filename)
 {
   static bool first_file = true;
 
-  printf ("%s==> %s <==\n", (first_file ? "" : "\n"), filename);
+  printf ("%s==> %s <==\n", (first_file ? "" : "\n"), quotef (filename));
   first_file = false;
 }
 

diff --git a/src/tail.c b/src/tail.c
index 2bc29cb5de04f61f54b3c50efbac35da95ef5b88..2ca27e835017346175001fa8276ae2e2b369199d 100644 (file)
--- a/src/tail.c
+++ b/src/tail.c
@@ -461,7 +461,7 @@ write_header (char const *prettyname)
 {
   static bool first_file = true;
 
-  printf ("%s==> %s <==\n", first_file ? "" : "\n", prettyname);
+  printf ("%s==> %s <==\n", first_file ? "" : "\n", quotef (prettyname));
   first_file = false;
 }
 

diff --git a/tests/head/quote-headers.sh b/tests/head/quote-headers.sh
new file mode 100755 (executable)
index 0000000..336db0e
--- /dev/null
+++ b/tests/head/quote-headers.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+# Ensure head quotes file names appropriately in headers
+# Before coreutils 9.12 'head ...' would not quote problematic file names.
+
+# Copyright (C) 2026 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
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ head
+
+NL='
+'
+
+touch "$NL" normal || framework_failure_
+
+head -n1 "$NL" normal >out || fail=1
+
+cat<<\EOF>exp || framework_failure_
+==> ''$'\n' <==
+
+==> normal <==
+EOF
+
+compare exp out || fail=1
+
+Exit $fail

diff --git a/tests/local.mk b/tests/local.mk
index cc7e20a46635ad205b66f43d59568da80801c2cd..63a437318607eb2bcaed87ab576cdfb530a51ba3 100644 (file)
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -197,6 +197,7 @@ all_tests =                                 \
   tests/tail/inotify-rotate-resources.sh       \
   tests/tail/inotify-dir-recreate.sh           \
   tests/tail/inotify-only-regular.sh           \
+  tests/tail/quote-headers.sh                  \
   tests/chmod/no-x.sh                          \
   tests/chgrp/basic.sh                         \
   tests/rm/dangling-symlink.sh                 \
@@ -368,6 +369,7 @@ all_tests =                                 \
   tests/head/head-n0.sh                                \
   tests/head/head-pos.sh                       \
   tests/head/head-write-error.sh               \
+  tests/head/quote-headers.sh                  \
   tests/misc/kill.sh                           \
   tests/cksum/b2sum.sh                         \
   tests/cksum/md5sum.pl                                \

diff --git a/tests/tail/quote-headers.sh b/tests/tail/quote-headers.sh
new file mode 100755 (executable)
index 0000000..2e173a1
--- /dev/null
+++ b/tests/tail/quote-headers.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+# Ensure tail quotes file names appropriately in headers
+# Before coreutils 9.12 'tail ...' would not quote problematic file names.
+
+# Copyright (C) 2026 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
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ tail
+
+NL='
+'
+
+touch "$NL" normal || framework_failure_
+
+tail -n1 "$NL" normal >out || fail=1
+
+cat<<\EOF>exp || framework_failure_
+==> ''$'\n' <==
+
+==> normal <==
+EOF
+
+compare exp out || fail=1
+
+Exit $fail