From d6c77c9647af5086323bcad325803114431d5901 Mon Sep 17 00:00:00 2001
From: akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 17 Mar 2009 05:56:59 +0000
Subject: [PATCH] * lib/pathname.rb (Pathname#sub): set $~ in block.binding.  
 [ruby-dev:38173]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@22988 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog                      |  5 +++++
 lib/pathname.rb                | 16 +++++++++++++++-
 test/pathname/test_pathname.rb |  9 +++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 379002b293..e18326a370 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Mar 17 14:56:26 2009  Tanaka Akira  <akr@fsij.org>
+
+	* lib/pathname.rb (Pathname#sub): set $~ in block.binding.
+	  [ruby-dev:38173]
+
 Mon Mar 16 16:37:22 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/tk/tcltklib.c (eventloop_sleep, lib_eventloop_core),
diff --git a/lib/pathname.rb b/lib/pathname.rb
index 1f1433634a..5c723a7c20 100644
--- a/lib/pathname.rb
+++ b/lib/pathname.rb
@@ -251,7 +251,21 @@ class Pathname
 
   # Return a pathname which is substituted by String#sub.
   def sub(pattern, *rest, &block)
-    self.class.new(@path.sub(pattern, *rest, &block))
+    if block
+      path = @path.sub(pattern, *rest) {|*args|
+        begin
+          old = Thread.current[:pathname_sub_matchdata]
+          Thread.current[:pathname_sub_matchdata] = $~
+          eval("$~ = Thread.current[:pathname_sub_matchdata]", block.binding)
+        ensure
+          Thread.current[:pathname_sub_matchdata] = old
+        end
+        yield *args
+      }
+    else
+      path = @path.sub(pattern, *rest)
+    end
+    self.class.new(path)
   end
 
   if File::ALT_SEPARATOR
diff --git a/test/pathname/test_pathname.rb b/test/pathname/test_pathname.rb
index 9b0b9c01e8..f94c123dec 100644
--- a/test/pathname/test_pathname.rb
+++ b/test/pathname/test_pathname.rb
@@ -381,6 +381,15 @@ class TestPathname < Test::Unit::TestCase
   def pathsub(path, pat, repl) Pathname.new(path).sub(pat, repl).to_s end
   defassert(:pathsub, "a.o", "a.c", /\.c\z/, ".o")
 
+  def test_sub_matchdata
+    result = Pathname("abc.gif").sub(/\..*/) {
+      assert_not_nil($~)
+      assert_equal(".gif", $~[0])
+      ".png"
+    }
+    assert_equal("abc.png", result.to_s)
+  end
+
   def root?(path)
     Pathname.new(path).root?
   end