rbinstall.rb: spec date from VCS

* tool/rbinstall.rb (Gem::Specification.load): obtain spec date from
  VCS for the case using git, RUBY_RELEASE_DATE is the last resort.
  probably fixes [Bug #9085].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43617 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Sat Nov  9 22:35:35 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* tool/rbinstall.rb (Gem::Specification.load): obtain spec date from
+	  VCS for the case using git, RUBY_RELEASE_DATE is the last resort.
+	  probably fixes [Bug #9085].
+
 Sat Nov  9 20:56:12 2013  Narihiro Nakamura  <authornari@gmail.com>
 
 	* ext/objspace/object_tracing.c: use declarations in internal.h.

tool/file2lastrev.rb

@@ -1,6 +1,9 @@
 #!/usr/bin/env ruby
 
 require 'optparse'
+
+# this file run with BASERUBY, which may be older than 1.9, so no
+# require_relative
 require File.expand_path('../vcs', __FILE__)
 
 Program = $0

tool/rbinstall.rb

@@ -19,10 +19,17 @@ require 'optparse'
 require 'optparse/shellwords'
 require 'ostruct'
 require 'rubygems'
+require_relative 'vcs'
 
 STDOUT.sync = true
 File.umask(0)
 
+begin
+  $vcs = VCS.detect(File.expand_path('../..', __FILE__))
+rescue VCS::NotFoundError
+  $vcs = nil
+end
+
 def parse_args(argv = ARGV)
   $mantype = 'doc'
   $destdir = nil
@@ -560,13 +567,20 @@ module Gem
       super
       yield(self) if defined?(yield)
       self.executables ||= []
-      self.date ||= RUBY_RELEASE_DATE
     end
 
     def self.load(path)
       src = File.open(path, "rb") {|f| f.read}
       src.sub!(/\A#.*/, '')
-      eval(src, nil, path)
+      spec = eval(src, nil, path)
+      spec.date ||= last_date(path) || RUBY_RELEASE_DATE
+      spec
+    end
+
+    def self.last_date(path)
+      return unless $vcs
+      return unless time = $vcs.get_revisions(path)[2]
+      time.strftime("%Y-%m-%d")
     end
 
     def to_ruby

tool/vcs.rb

@@ -1,5 +1,7 @@
 # vcs
 
+require 'time'
+
 ENV.delete('PWD')
 
 unless File.respond_to? :realpath
@@ -40,10 +42,11 @@ class VCS
   # +path+ was modified.
   def get_revisions(path)
     path = relative_to(path)
-    last, changed, *rest = Dir.chdir(@srcdir) {self.class.get_revisions(path)}
+    last, changed, modified, *rest = Dir.chdir(@srcdir) {self.class.get_revisions(path)}
     last or raise "last revision not found"
     changed or raise "changed revision not found"
-    return last, changed, *rest
+    modified &&= Time.parse(modified)
+    return last, changed, modified, *rest
   end
 
   def relative_to(path)
@@ -84,7 +87,8 @@ class VCS
         end
       end
       _, last, _, changed, _ = info_xml.split(/revision="(\d+)"/)
-      [last, changed]
+      modified = info_xml[/<date>([^<>]*)/, 1]
+      [last, changed, modified]
     end
   end
 
@@ -95,8 +99,14 @@ class VCS
       logcmd = %Q[git log -n1 --grep="^ *git-svn-id: .*@[0-9][0-9]* "]
       idpat = /git-svn-id: .*?@(\d+) \S+\Z/
       last = `#{logcmd}`[idpat, 1]
-      changed = path ? `#{logcmd} "#{path}"`[idpat, 1] : last
-      [last, changed]
+      if path
+        log = `#{logcmd} "#{path}"`
+        changed = log[idpat, 1]
+        modified = `git log --format=%ai -- #{path}`
+      else
+        changed = last
+      end
+      [last, changed, modified]
     end
   end
 end