wc: don't miscount /sys and similar file systems

Fix similar problems in head, od, split, tac, and tail.
Reported by George Shuklin in: http://bugs.gnu.org/18621
* NEWS: Document this.
* src/head.c (elseek): Move up.
(elide_tail_bytes_pipe, elide_tail_lines_pipe): New arg
CURRENT_POS.  All uses changed.
(elide_tail_bytes_file, elide_tail_lines_file):
New arg ST and remove arg SIZE.  All uses changed.
* src/head.c (elide_tail_bytes_file):
* src/od.c (skip): Avoid optimization for /sys files, where
st_size is bogus and st_size == st_blksize.
Don't report error at EOF when not optimizing.
* src/head.c, src/od.c, src/tail.c: Include "stat-size.h".
* src/split.c (input_file_size): New function.
(bytes_split, lines_chunk_split, bytes_chunk_extract): New arg
INITIAL_READ.  All uses changed. Use it to double-check st_size.
* src/tac.c (tac_seekable): New arg FILE_POS.  All uses changed.
(copy_to_temp): Return size of temp file.  All uses changed.
* src/tac.c (tac_seekable):
* src/tail.c (tail_bytes):
* src/wc.c (wc):
Don't trust st_size; double-check by reading.
* src/wc.c (wc): New arg CURRENT_POS.  All uses changed.
* tests/local.mk (all_tests): Add tests/misc/wc-proc.sh,
tests/misc/od-j.sh, tests/tail-2/tail-c.sh.
* tests/misc/head-c.sh:
* tests/misc/tac-2-nonseekable.sh:
* tests/split/b-chunk.sh:
Add tests for problems with /proc and /sys files.
* tests/misc/od-j.sh, tests/misc/wc-proc.sh, tests/tail-2/tail-c.sh:
New files.

1 files changed, 39 insertions, 0 deletions

diff --git a/tests/misc/od-j.sh b/tests/misc/od-j.sh
new file mode 100755
index 000000000..a40a99ff7
--- /dev/null
+++ b/tests/misc/od-j.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+# Verify that 'od -j N' skips N bytes of input.
+
+# Copyright 2014 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 <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ od
+
+for file in ${srcdir=.}/tests/init.sh /proc/version /sys/kernel/profiling; do
+  test -r $file || continue
+
+  cp -f $file copy &&
+  bytes=$(wc -c < copy) || framework_failure_
+
+  od -An $file > exp || fail=1
+  od -An -j $bytes $file $file > out || fail=1
+  compare out exp || fail=1
+
+  od -An -j 4096 copy copy > exp1 2> experr1; expstatus=$?
+  od -An -j 4096 $file $file > out1 2> err1; status=$?
+  test $status -eq $expstatus || fail=1
+  compare out1 exp1 || fail=1
+  compare err1 experr1 || fail=1
+done
+
+Exit $fail