1 files changed, 123 insertions, 0 deletions
diff --git a/tests/misc/pwd-long.sh b/tests/misc/pwd-long.sh
new file mode 100755
index 0000000..34a3b54
--- /dev/null
+++ b/tests/misc/pwd-long.sh
@@ -0,0 +1,123 @@
+#!/bin/sh
+# -*- perl -*-
+# Ensure that pwd works even when run from a very deep directory.
+
+# Copyright (C) 2006-2022 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_ pwd
+
+require_readable_root_
+require_perl_
+
+ARGV_0=$0
+export ARGV_0
+
+# Don't use CuTmpdir here, since File::Temp's use of rmtree can't
+# remove the deep tree we create.
+$PERL -Tw -I"$abs_srcdir/tests" -MCuSkip -- - <<\EOF
+
+# Show that pwd works even when the length of the resulting
+# directory name is longer than PATH_MAX.
+use strict;
+
+(my $ME = $ENV{ARGV_0}) =~ s|.*/||;
+
+sub normalize_to_cwd_relative ($$$)
+{
+  my ($dir, $dev, $ino) = @_;
+  my $slash = -1;
+  my $next_slash;
+  while (1)
+    {
+      $slash = index $dir, '/', $slash + 1;
+      $slash <= -1
+        and die "$ME: $dir does not contain old CWD\n";
+      my $dir_prefix = $slash ? substr ($dir, 0, $slash) : '/';
+      my ($d, $i) = (stat $dir_prefix)[0, 1];
+      defined $d && defined $i
+        or die "$ME: $dir_prefix: stat failed: $!\n";
+      $d eq $dev && $i eq $ino
+        and return substr $dir, $slash + 1;
+    }
+}
+
+# Set up a safe, well-known environment
+$ENV{IFS}  = '';
+
+# Taint checking requires a sanitized $PATH.  This script performs no $PATH
+# search, so on most Unix-based systems, it is fine simply to clear $ENV{PATH}.
+# However, on Cygwin, it's used to find cygwin1.dll, so set it.
+$ENV{PATH} = '/bin:/usr/bin';
+
+# Save CWD's device and inode numbers.
+my ($dev, $ino) = (stat '.')[0, 1];
+
+# Construct the expected "."-relative part of pwd's output.
+my $z = 'z' x 31;
+my $n = 256;
+my $expected = "/$z" x $n;
+# Remove the leading "/".
+substr ($expected, 0, 1) = '';
+
+my $i = 0;
+do
+  {
+    mkdir $z, 0700
+      or CuSkip::skip "$ME: skipping this test; cannot create long "
+        . "directory name at depth $i: $!\n";
+    chdir $z
+  }
+until (++$i == $n);
+
+my $abs_top_builddir = $ENV{abs_top_builddir};
+$abs_top_builddir
+  or die "$ME: envvar abs_top_builddir not defined\n";
+my $build_src_dir = "$abs_top_builddir/src";
+$build_src_dir =~ m!^([-+.:/\w]+)$!
+  or CuSkip::skip "$ME: skipping this test; odd build source directory name:\n"
+    . "$build_src_dir\n";
+$build_src_dir = $1;
+
+my $pwd_binary = "$build_src_dir/pwd";
+
+-x $pwd_binary
+  or die "$ME: $pwd_binary is not an executable file\n";
+chomp (my $actual = qx!$pwd_binary!);
+
+# Convert the absolute name from pwd into a $CWD-relative name.
+# This is necessary in order to avoid a spurious failure when run
+# from a directory in a bind-mounted partition.  What happens is
+# pwd reads a ".." that contains two or more entries with identical
+# dev,ino that match the ones we're looking for, and it chooses a
+# name that does not correspond to the one already recorded in $CWD.
+$actual = normalize_to_cwd_relative $actual, $dev, $ino;
+
+if ($expected ne $actual)
+  {
+    my $e_len = length $expected;
+    my $a_len = length $actual;
+    warn "expected len: $e_len\n";
+    warn "actual len:   $a_len\n";
+    warn "expected: $expected\n";
+    warn "actual: $actual\n";
+    exit 1;
+  }
+EOF
+
+fail=$?
+
+Exit $fail