* gem_prelude.rb: load full rubygems at LoadError for activation

  check.  [ruby-core:29486]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@28200 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 33 insertions, 9 deletions

diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index d2e0f2cb5d..1dee815a15 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -1020,8 +1020,6 @@ end
 
 module Kernel
 
-  undef gem if respond_to? :gem # defined in gem_prelude.rb on 1.9
-
   ##
   # Use Kernel#gem to activate a specific version of +gem_name+.
   #
@@ -1098,13 +1096,34 @@ end
 
 require 'rubygems/config_file'
 
+class << Gem
+  verbose, debug = $VERBOSE, $DEBUG
+  $VERBOSE = $DEBUG = nil
+
+  ##
+  #
+  # Called from the custom_require to attempt to activate +path+
+  # Internal use only.
+
+  def try_activate(path) # :doc:
+    spec = Gem.searcher.find(path)
+    return false unless spec
+
+    Gem.activate(spec.name, "= #{spec.version}")
+    return true
+  end
+
+ensure
+  $VERBOSE, $DEBUG = verbose, debug
+end
+
 ##
 # Enables the require hook for RubyGems.
 #
 # Ruby 1.9 allows --disable-gems, so we require it when we didn't detect a Gem
 # constant at rubygems.rb load time.
 
-require 'rubygems/custom_require' if gem_disabled or RUBY_VERSION < '1.9'
+require 'rubygems/custom_require'
 
 Gem.clear_paths
 
diff --git a/lib/rubygems/custom_require.rb b/lib/rubygems/custom_require.rb
index 43b3136b60..36e3c78911 100644
--- a/lib/rubygems/custom_require.rb
+++ b/lib/rubygems/custom_require.rb
@@ -4,8 +4,6 @@
 # See LICENSE.txt for permissions.
 #++
 
-require 'rubygems'
-
 module Kernel
 
   ##
@@ -31,10 +29,17 @@ module Kernel
     gem_original_require path
   rescue LoadError => load_error
     if load_error.message.end_with?(path) and
-       spec = Gem.searcher.find(path) then
-      Gem.activate(spec.name, "= #{spec.version}")
-      gem_original_require path
+        begin
+          Gem.try_activate(path)
+        rescue Gem::LoadError => load_error
+          pat = "#{__FILE__}:#{__LINE__-2}:in "
+          bt = load_error.backtrace
+          num = bt.index {|e| e.start_with?(pat)} and bt.shift(num+2)
+          raise load_error
+        end
+      retry
     else
+      load_error.backtrace.shift(2)
       raise load_error
     end
   end
@@ -42,5 +47,5 @@ module Kernel
   private :require
   private :gem_original_require
 
-end
+end unless Kernel.private_method_defined?(:gem_original_require)