From b01f0cab31d34451d00f1ee1ecffb79a7e11851b Mon Sep 17 00:00:00 2001
From: akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 11 Oct 2003 06:42:41 +0000
Subject: [PATCH] * lib/pathname.rb (realpath): re-implemented.  
 (realpath_root?, realpath_rec): removed

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4743 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog       |  6 ++--
 lib/pathname.rb | 86 ++++++++++++++++++-------------------------------
 2 files changed, 35 insertions(+), 57 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index aa59c423a4..772776f184 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,7 +1,7 @@
-Sat Oct 11 14:35:14 2003  Tanaka Akira  <akr@m17n.org>
+Sat Oct 11 15:41:06 2003  Tanaka Akira  <akr@m17n.org>
 
-	* lib/pathname.rb (realpath_rec): fix handling of symlink to absolute
-	  path.
+	* lib/pathname.rb (realpath): re-implemented.
+	  (realpath_root?, realpath_rec): removed
 
 Sat Oct 11 10:19:39 2003  Shugo Maeda  <shugo@ruby-lang.org>
 
diff --git a/lib/pathname.rb b/lib/pathname.rb
index eff3b6cd15..7bd007a2c8 100644
--- a/lib/pathname.rb
+++ b/lib/pathname.rb
@@ -111,65 +111,43 @@ class Pathname
   # it may return relative pathname.
   # Otherwise it returns absolute pathname.
   def realpath(force_absolute=true)
-    path = @path
-    stats = {}
-    if %r{\A/} =~ path || realpath_root?('.', stats)
-      resolved = '/'
-    else
-      resolved = '.'
-    end
-    resolved = realpath_rec(resolved, path, stats)
-    if %r{\A/} !~ resolved && force_absolute
-      # Note that Dir.pwd and resolved has no symlinks.
-      Pathname.new(File.join(Dir.pwd, resolved)).cleanpath
-    else
-      Pathname.new(resolved)
-    end
-  end
-
-  def realpath_root?(path, stats) # :nodoc:
-    path_stat = stats[path] ||= File.lstat(path)
-    parent = path == '.' ? '..' : File.join(path, '..')
-    parent_stat = stats[parent] ||= File.lstat(parent)
-    path_stat.dev == parent_stat.dev && path_stat.ino == parent_stat.ino
-  end
-
-  def realpath_rec(resolved, unresolved, stats, rec={}) # :nodoc:
-    unresolved.scan(%r{[^/]+}) {|f|
-      next if f == '.'
-      if f == '..'
-        case resolved
-        when '/'
-          # Since the parent directory of '/' is '/', do nothing.
-        when '.'
-          resolved = '..'
-          resolved = '/' if realpath_root?(resolved, stats)
-        when %r{(\A|/)\.\.\z}
-          resolved << '/..'
-          resolved = '/' if realpath_root?(resolved, stats)
-        when %r{/}
-          resolved = File.dirname(resolved)
-        else
-          resolved = '.'
-        end
+    top = %r{\A/} =~ @path ? '/' : ''
+    unresolved = @path.scan(%r{[^/]+})
+    resolved = []
+    
+    until unresolved.empty?
+      case unresolved.last
+      when '.'
+        unresolved.pop
+      when '..'
+        resolved.unshift unresolved.pop
       else
-        path = resolved == '.' ? f : File.join(resolved, f)
-        if File.lstat(path).symlink?
-          raise Errno::ELOOP.new(path) if rec.include? path
-          link = File.readlink path
-          resolved = '/' if %r{\A/} =~ link
-          begin
-            rec[path] = true
-            resolved = realpath_rec(resolved, link, stats, rec)
-          ensure
-            rec.delete path
+        path = top + unresolved.join('/')
+        if FileTest.symlink? path
+          link = File.readlink(path)
+          if %r{\A/} =~ link
+            top = '/'
+            unresolved = link.scan(%r{[^/]+})
+          else
+            unresolved.pop
+            unresolved.concat link.scan(%r{[^/]+})
           end
         else
-          resolved = path
+          resolved.unshift unresolved.pop
         end
       end
-    }
-    resolved
+    end
+    
+    if resolved.empty?
+      path = top.empty? ? '.' : top
+    else
+      path = top + resolved.join('/')
+    end
+    
+    # Note that Dir.pwd has no symlinks.
+    path = File.join(Dir.pwd, path) if %r{\A/} !~ path && force_absolute
+
+    Pathname.new(path).cleanpath
   end
 
   # parent method returns parent directory, i.e. ".." is joined at last.