grep: -r no longer follows symlinks; use fts

Change -r to follow only command-line symlinks, and by default to
read only devices named on the command line.  This is a simple
way to get a more-useful behavior when searching random
directories; the idea is to use 'find' if you want something fancy.
-R acts as before and gets a new alias --dereference-recursive.
The code now uses fts internally, so it is more robust and
faster with large hierarchies.
* .gitignore: Remove lib/savedir.c, lib/savedir.h.
* tests/symlink: New file
* Makefile.boot (LIB_OBJS_core): Remove isdir.o, savedir.o.
Perhaps other changes are needed too, but I'm not sure what
this makefile is for.
* NEWS: Document changes.
* doc/grep.texi (File and Directory Selection): Likewise.
* bootstrap.conf (gnulib_modules): Remove dirent, dirname, isdir, open.
Add fstatat, fts, openat-safer.
* lib/Makefile.am (libgreputils_a_SOURCES): Remove savedir.c, savedir.h.
* lib/savedir.c, lib/savedir.h: Remove.
* po/POTFILES.in: Add lib/openat-die.c.
* src/main.c: Include fcntl-safer.h, fts_.h.  Don't include
isdir.h, savedir.h.
(struct stats, stats_base): Remove.
(long_options, usage, main): Add --dereference-recursive and
implement -r vs -R.
(filename_prefix_len, fts_options): New static vars.
(basic_fts_options, READ_COMMAND_LINE_DEVICES): New constants.
(devices): Now defaults to READ_COMMAND_LINE_DEVICES.
(reset, grep): Now takes just struct stat rather than file name and
struct stats.  All callers changed.
(fillbuf): Now takes struct stat reather than struct stats.
All callers changed.
(grep): Don't worry about recursing too deeply; fts and grepdesc
handle this now.
(is_device_mode, grepdirent, grepdesc, grep_command_line_args):
New functions.
(grepfile): New args DIRDESC, FOLLOW, COMMAND_LINE.  Remove struct stats
arg.  All callers changed.  Use openat_safer rather than open.
Use desc == STDIN_FILENO to tell whether we're reading "-".
Don't worry about EINTR when closing -- not possible, since we're
not catching signals.
* tests/Makefile.am (TESTS): Add symlink.
* tests/symlink: New file.

2 files changed, 66 insertions, 0 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index c2cd2f7d..13061fed 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -82,6 +82,7 @@ TESTS =						\
   spencer1					\
   spencer1-locale				\
   status					\
+  symlink					\
   turkish-I					\
   warn-char-classes				\
   word-delim-multibyte				\
diff --git a/tests/symlink b/tests/symlink
new file mode 100755
index 00000000..012d8f8f
--- /dev/null
+++ b/tests/symlink
@@ -0,0 +1,65 @@
+#!/bin/sh
+# Check that "grep -r" does the right thing with symbolic links.
+
+# Copyright (C) 2012 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/>.
+
+# written by Paul Eggert
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+
+mkdir dir || framework_failure_
+echo a > dir/a || framework_failure_
+echo b > dir/b || framework_failure_
+ln -s a dir/c || framework_failure_
+ln -s . dir/d || framework_failure_
+ln -s dangling dir/e || framework_failure_
+
+touch out || framework_failure_
+
+for recursion in '' -r -R
+do
+  for files in '' '*'
+  do
+    case $recursion,$files in
+      -R,* | *,'*') expected_status=2 ;;
+      *) expected_status=0 ;;
+    esac
+
+    (cd dir && grep $recursion '^' $files <a ) >grepout
+    test $? -eq $expected_status || fail=1
+
+    case $recursion,$files in
+      ,)
+         exp='a\n' ;;
+      ,'*' | -R,)
+         exp='a:a\nb:b\nc:a\n' ;;
+      -r,)
+         exp='a:a\nb:b\n' ;;
+      -r,'*')
+         exp='a:a\nb:b\nc:a\nd/a:a\nd/b:b\n' ;;
+      -R,'*')
+         exp='a:a\nb:b\nc:a\nd/a:a\nd/b:b\nd/c:a\n' ;;
+      *)
+         framework_failure_ ;;
+    esac
+
+    printf "$exp" >exp || framework_failure_
+    LC_ALL=C sort grepout >out || fail=1
+    compare exp out || fail=1
+  done
+done
+
+Exit $fail