du: -x should not count files in other file systems

This fixes Bug#10293, which I guess was introduced in commit
95c948b06a dated 2003-10-02.
* NEWS: Document fix.
* src/du.c (process_file): Don't count files in different file
systems if -x is given.
* tests/du/one-file-system: Test for this bug.

NEWS

@@ -4,6 +4,9 @@ GNU coreutils NEWS                                    -*- outline -*-
 
 ** Bug fixes
 
+  du -x no longer counts root directories of other file systems.
+  [bug introduced in coreutils-5.1.0]
+
   ls --color many-entry-directory was uninterruptible for too long
   [bug introduced in coreutils-5.2.1]
 

src/du.c

@@ -443,6 +443,9 @@ process_file (FTS *fts, FTSENT *ent)
               error (0, ent->fts_errno, _("cannot access %s"), quote (file));
               return false;
             }
+
+          if (fts->fts_options & FTS_XDEV && fts->fts_dev != sb->st_dev)
+            excluded = true;
         }
 
       if (excluded

tests/du/one-file-system

@@ -1,6 +1,5 @@
 #!/bin/sh
-# Test for a bug in fts's handling of FTS_XDEV, the flag behind
-# du's --one-file-system (-x) option.
+# Test for bugs in du's --one-file-system (-x) option.
 
 # Copyright (C) 2006-2011 Free Software Foundation, Inc.
 
@@ -19,9 +18,11 @@
 
 . "${srcdir=.}/init.sh"; path_prepend_ ../src
 print_ver_ du
+cleanup_() { rm -rf "$other_partition_tmpdir"; }
+. "$abs_srcdir/other-fs-tmpdir"
 
-mkdir -p b/c y/z || framework_failure_
-
+mkdir -p b/c y/z d "$other_partition_tmpdir/x" || framework_failure_
+ln -s "$other_partition_tmpdir/x" d || framework_failure_
 
 # Due to a used-uninitialized variable, the "du -x" from coreutils-6.6
 # would not traverse into second and subsequent directories listed
@@ -37,4 +38,12 @@ EOF
 
 compare exp out || fail=1
 
+# "du -xL" reported a zero count for a file in a different file system,
+# instead of ignoring it.
+du -xL d > u || fail=1
+sed 's/^[0-9][0-9]*	//' u > out1
+echo d > exp1 || fail=1
+
+compare exp1 out1 || fail=1
+
 Exit $fail