Revamp tar_getcwd/normalize_filename stuff.

The changes are based on the discussion with Nathan.

* src/common.h (normalize_filename): Take two arguments. All
callers updated.
(tar_getcwd): Replaced with ..
(tar_getcdpath): New proto.
* src/misc.c (normalize_filename): Take two arguments.
(chdir_arg): Populate cwd along with creating the
structure.
(tar_getcwd): Removed.
(tar_getcdpath): New function.

* tests/incr09.at: New test case.
* tests/Makefile.am: Add new tests.
* tests/testsuite.at: Likewise.

src/common.h

@@ -596,7 +596,7 @@ void skip_member (void);
 void assign_string (char **dest, const char *src);
 int unquote_string (char *str);
 char *zap_slashes (char *name);
-char *normalize_filename (const char *name);
+char *normalize_filename (int cdidx, const char *name);
 void normalize_filename_x (char *name);
 void replace_prefix (char **pname, const char *samp, size_t slen,
 		     const char *repl, size_t rlen);
@@ -609,7 +609,7 @@ char *namebuf_name (namebuf_t buf, const char *name);
 void namebuf_add_dir (namebuf_t buf, const char *name);
 char *namebuf_finish (namebuf_t buf);
 
-const char *tar_getcwd (void);
+const char *tar_getcdpath (int);
 const char *tar_dirname (void);
 
 /* Represent N using a signed integer I such that (uintmax_t) I == N.

src/incremen.c

@@ -280,7 +280,7 @@ free_directory (struct directory *dir)
 static struct directory *
 attach_directory (const char *name)
 {
-  char *cname = normalize_filename (name);
+  char *cname = normalize_filename (chdir_current, name);
   struct directory *dir = make_directory (name, cname);
   if (dirtail)
     dirtail->next = dir;
@@ -370,7 +370,7 @@ find_directory (const char *name)
     return 0;
   else
     {
-      char *caname = normalize_filename (name);
+      char *caname = normalize_filename (chdir_current, name);
       struct directory *dir = make_directory (name, caname);
       struct directory *ret = hash_lookup (directory_table, dir);
       free_directory (dir);

src/misc.c

@@ -273,7 +273,7 @@ normalize_filename_x (char *file_name)
    Return a normalized newly-allocated copy.  */
 
 char *
-normalize_filename (const char *name)
+normalize_filename (int cdidx, const char *name)
 {
   char *copy = NULL;
 
@@ -285,7 +285,7 @@ normalize_filename (const char *name)
          getcwd is slow, it might fail, and it does not necessarily
          return a canonical name even when it succeeds.  Perhaps we
          can use dev+ino pairs instead of names?  */
-      const char *cwd = tar_getcwd ();
+      const char *cwd = tar_getcdpath (cdidx);
       size_t copylen;
       bool need_separator;
       
@@ -888,7 +888,7 @@ chdir_arg (char const *dir)
       if (! wd_count)
 	{
 	  wd[wd_count].name = ".";
-	  wd[wd_count].cwd = NULL;
+	  wd[wd_count].cwd = xgetcwd ();
 	  wd[wd_count].fd = AT_FDCWD;
 	  wd_count++;
 	}
@@ -906,7 +906,14 @@ chdir_arg (char const *dir)
     }
 
   wd[wd_count].name = dir;
-  wd[wd_count].cwd = NULL;
+  if (IS_ABSOLUTE_FILE_NAME (wd[wd_count].name))
+    wd[wd_count].cwd = xstrdup (wd[wd_count].name);
+  else
+    {
+      namebuf_t nbuf = namebuf_create (wd[wd_count - 1].cwd);
+      namebuf_add_dir (nbuf, wd[wd_count].name);
+      wd[wd_count].cwd = namebuf_finish (nbuf);
+    }
   wd[wd_count].fd = 0;
   return wd_count++;
 }
@@ -987,37 +994,16 @@ tar_dirname (void)
 }
 
 const char *
-tar_getcwd (void)
+tar_getcdpath (int idx)
 {
-  static char *cwd;
-  namebuf_t nbuf;
-  int i;
-
-  if (!cwd)
-    cwd = xgetcwd ();
   if (!wd)
-    return cwd;
-  
-  if (0 == chdir_current || !wd[chdir_current].cwd)
     {
-      if (IS_ABSOLUTE_FILE_NAME (wd[chdir_current].name))
-	{
-	  wd[chdir_current].cwd = xstrdup (wd[chdir_current].name);
-	  return wd[chdir_current].cwd;
-	}
-      if (!wd[0].cwd)
-	wd[0].cwd = cwd;
-
-      for (i = chdir_current - 1; i > 0; i--)
-	if (wd[i].cwd)
-	  break;
-      
-      nbuf = namebuf_create (wd[i].cwd);
-      for (i++; i <= chdir_current; i++)
-	namebuf_add_dir (nbuf, wd[i].name);
-      wd[chdir_current].cwd = namebuf_finish (nbuf);
+      static char *cwd;
+      if (!cwd)
+	cwd = xgetcwd ();
+      return cwd;
     }
-  return wd[chdir_current].cwd;
+  return wd[idx].cwd;
 }
 
 void

src/names.c

@@ -1238,13 +1238,11 @@ collect_and_sort_names (void)
   namelist = merge_sort (namelist, num_names, compare_names);
 
   num_names = 0;
-  nametab = hash_initialize (0, 0,
-			     name_hash,
-			     name_compare, NULL);
+  nametab = hash_initialize (0, 0, name_hash, name_compare, NULL);
   for (name = namelist; name; name = next_name)
     {
       next_name = name->next;
-      name->caname = normalize_filename (name->name);
+      name->caname = normalize_filename (name->change_dir, name->name);
       if (prev_name)
 	{
 	  struct name *p = hash_lookup (nametab, name);