Improve listed incremental dumps.

The modified algorithm tries to avoid dumping the same
directory twice and ensures the order of the directories
in the resulting archive is the same, whatever their order
on the command line.  It also fixes the operation of
--listed-incremental -C.

* gnulib.modules: Add canonicalize
* src/common.h (incremental_level): New global.
(check_exclusion_tags): first argument is const.
(get_directory_contents): Add third argument.
(zap_slashes, normalize_filename): New prototypes.
(chdir_count): New prototype.
(WARN_VERBOSE_WARNINGS): New define.
(WARN_ALL): Exclude WARN_VERBOSE_WARNINGS.
* src/compare.c (diff_dumpdir): Update the call to get_directory_contents.
* src/create.c (check_exclusion_tags): First argument is const.
Use ISSLASH and DIRECTORY_SEPARATOR instead of referring to '/'.

* src/incremen.c (struct directory): New member `caname'.
(hash_directory_name): Rename to hash_directory_canonical_name. Operate
on the canonical name.
(compare_directory_names): Rename to compare_directory_canonical_names.
Operate on the canonical name.
(make_directory): Take two arguments.
(free_directory): Free caname.
(attach_directory): Create caname.
(find_directory): Use caname for lookups.
(PD_VERBOSE): Remove.
(PD_FORCE_INIT): New define.
(procdir): First argument is const.
Reinitialize directory if PD_FORCE_INIT bit is set.
Do not use PD_VERBOSE or verbose_option for issuing warnings.
Rely on WARNOPT instead.
Always set *entry.
(scan_directory): Take three arguments. The third one is a boolean
which is true if the directory is explicitly mentioned on the command
line.
(get_directory_contents): Remove.  Use scan_directory instead.
All callers updated.
(read_directory_file): Truncate the file if --level=0 is given.
* src/misc.c: Include canonicalize.h
(zap_slashes, normalize_filename): New functions.
(chdir_count): New function.
* src/names.c (add_hierarchy_to_namelist): Take three arguments, as
get_directory_contents and scan_directory.
(collect_and_sort_names): Allow at most one -C, before file name
arguments.
Read directory file after eventual changing to another directory.
Avoid adding the same directory under different pathnames to
the list.
* src/tar.c: New option --level.

* tests/incr03.at, tests/incr04.at, tests/listed01.at,
tests/listed02.at, tests/rename01.at, tests/rename02.at,
tests/rename03.at: Update for new tar behavior.
* tests/multiv01.at: Do not use --listed-incremental.

src/common.h

@@ -1,7 +1,7 @@
 /* Common declarations for the tar program.
 
    Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1999, 2000, 2001,
-   2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+   2003, 2004, 2005, 2006, 2007, 2008, 2009 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
@@ -185,6 +185,8 @@ GLOBAL enum old_files old_files_option;
 
 /* Specified file name for incremental list.  */
 GLOBAL const char *listed_incremental_option;
+/* Incremental dump level */
+GLOBAL int incremental_level;
 /* Check device numbers when doing incremental dumps. */
 GLOBAL bool check_device_option;
 
@@ -322,15 +324,22 @@ GLOBAL char const *index_file_name;
 struct name
   {
     struct name *next;          /* Link to the next element */
+    struct name *prev;          /* Link to the previous element */
     int change_dir;		/* Number of the directory to change to.
 				   Set with the -C option. */
     uintmax_t found_count;	/* number of times a matching file has
 				   been found */
     int matching_flags;		/* this name is a regexp, not literal */
-    char const *dir_contents;	/* for incremental_option */
-
+    
     size_t length;		/* cached strlen(name) */
-    char name[1];
+    char *name;
+
+    /* The following members are used for incremental dumps only */
+    char const *dir_contents;	/* directory contents  */
+    struct name *parent;        /* pointer to the parent hierarchy */
+    struct name *child;         /* pointer to the first child */
+    struct name *sibling;       /* pointer to the next sibling */
+    char *caname;               /* canonical name */ 
   };
 
 /* Obnoxious test to see if dimwit is trying to dump the archive.  */
@@ -440,7 +449,7 @@ void write_eot (void);
 void check_links (void);
 void exclusion_tag_warning (const char *dirname, const char *tagname,
 			    const char *message);
-enum exclusion_tag_type check_exclusion_tags (char *dirname,
+enum exclusion_tag_type check_exclusion_tags (const char *dirname,
 					      const char **tag_file_name);
      
 #define GID_TO_CHARS(val, where) gid_to_chars (val, where, sizeof (where))
@@ -497,7 +506,7 @@ char *dumpdir_next (dumpdir_iter_t itr);
 char *dumpdir_first (dumpdir_t dump, int all, dumpdir_iter_t *pitr);
 
 
-const char *get_directory_contents (char *dir_name, dev_t device);
+const char *scan_directory (char *dir_name, dev_t device, bool cmdline);
 const char *append_incremental_renames (const char *dump);
 void read_directory_file (void);
 void write_directory_file (void);
@@ -565,6 +574,8 @@ void skip_member (void);
 void assign_string (char **dest, const char *src);
 char *quote_copy_string (const char *str);
 int unquote_string (char *str);
+char *zap_slashes (char *name);
+char *normalize_filename (const char *name);
 
 void code_ns_fraction (int ns, char *p);
 char const *code_timespec (struct timespec ts, char *sbuf);
@@ -594,6 +605,7 @@ int deref_stat (bool deref, char const *name, struct stat *buf);
 
 int chdir_arg (char const *dir);
 void chdir_do (int dir);
+int chdir_count (void);
 
 void close_diag (char const *name);
 void open_diag (char const *name);
@@ -629,7 +641,7 @@ void name_add_dir (const char *name);
 void name_term (void);
 const char *name_next (int change_dirs);
 void name_gather (void);
-struct name *addname (char const *string, int change_dir);
+struct name *addname (char const *string, int change_dir, struct name *parent);
 bool name_match (const char *name);
 void names_notfound (void);
 void collect_and_sort_names (void);
@@ -774,7 +786,10 @@ void checkpoint_run (bool do_write);
 #define WARN_UNKNOWN_KEYWORD     0x00020000
 #define WARN_XDEV                0x00040000
 
-#define WARN_ALL                 0xffffffff
+/* The warnings composing WARN_VERBOSE_WARNINGS are enabled by default
+   in verbose mode */
+#define WARN_VERBOSE_WARNINGS    (WARN_RENAME_DIRECTORY|WARN_NEW_DIRECTORY)
+#define WARN_ALL                 (0xffffffff & ~WARN_VERBOSE_WARNINGS)
 
 void set_warning_option (const char *arg);