add support for ENV GEM_SPEC

lib/rubygems.rb

@@ -374,6 +374,10 @@ def self.path
     paths.path
   end
 
+  def self.spec_cache_dir
+    paths.spec_cache_dir
+  end
+
   ##
   # Quietly ensure the Gem directory +dir+ contains all the proper
   # subdirectories.  If we can't create a directory due to a permission

lib/rubygems/commands/environment_command.rb

@@ -99,6 +99,8 @@ def execute
 
       out << "  - EXECUTABLE DIRECTORY: #{Gem.bindir}\n"
 
+      out << "  - SPEC CACHE DIRECTORY: #{Gem.spec_cache_dir}\n"
+
       out << "  - RUBYGEMS PLATFORMS:\n"
       Gem.platforms.each do |platform|
         out << "    - #{platform}\n"

lib/rubygems/commands/sources_command.rb

@@ -48,7 +48,7 @@ def execute
                        options[:update])
 
     if options[:clear_all] then
-      path = File.join Gem.user_home, '.gem', 'specs'
+      path = Gem.spec_cache_dir
       FileUtils.rm_rf path
 
       unless File.exist? path then

lib/rubygems/defaults.rb

@@ -14,6 +14,14 @@ def self.default_sources
     %w[https://rubygems.org/]
   end
 
+  ##
+  # Default spec directory path to be used if an alternate value is not
+  # specified in the environment
+
+  def self.default_spec_cache_dir
+    File.join Gem.user_home, '.gem', 'specs'
+  end
+
   ##
   # Default home directory path to be used if an alternate value is not
   # specified in the environment

lib/rubygems/path_support.rb

@@ -12,6 +12,10 @@ class Gem::PathSupport
   # Array of paths to search for Gems.
   attr_reader :path
 
+  ##
+  # Directory with spec cache
+  attr_reader :spec_cache_dir # :nodoc:
+
   ##
   #
   # Constructor. Takes a single argument which is to be treated like a
@@ -28,6 +32,8 @@ def initialize(env=ENV)
     end
 
     self.path = env["GEM_PATH"] || ENV["GEM_PATH"]
+
+    @spec_cache_dir =  env["GEM_SPEC"] || ENV["GEM_SPEC"] || Gem.default_spec_cache_dir
   end
 
   private

lib/rubygems/source.rb

@@ -58,8 +58,7 @@ def hash
   def cache_dir(uri)
     # Correct for windows paths
     escaped_path = uri.path.sub(/^\/([a-z]):\//i, '/\\1-/')
-    root = File.join Gem.user_home, '.gem', 'specs'
-    File.join root, "#{uri.host}%#{uri.port}", File.dirname(escaped_path)
+    File.join Gem.spec_cache_dir, "#{uri.host}%#{uri.port}", File.dirname(escaped_path)
   end
 
   def update_cache?

lib/rubygems/spec_fetcher.rb

@@ -38,7 +38,6 @@ def self.fetcher=(fetcher) # :nodoc:
   end
 
   def initialize
-    @dir = File.join Gem.user_home, '.gem', 'specs'
     @update_cache = File.stat(Gem.user_home).uid == Process.uid
 
     @specs = {}

lib/rubygems/test_case.rb

@@ -142,6 +142,7 @@ def setup
 
     @gemhome  = File.join @tempdir, 'gemhome'
     @userhome = File.join @tempdir, 'userhome'
+    ENV["GEM_SPEC"] = File.join @tempdir, 'spec_cache'
 
     @orig_ruby = if ENV['RUBY'] then
                    ruby = Gem.instance_variable_get :@ruby

test/rubygems/test_gem_commands_install_command.rb

@@ -167,8 +167,7 @@ def test_execute_bad_source
 
     # This is needed because we need to exercise the cache path
     # within SpecFetcher
-    path = File.join Gem.user_home, '.gem', 'specs', "not-there.nothing%80",
-                                    "latest_specs.4.8"
+    path = File.join Gem.spec_cache_dir, "not-there.nothing%80", "latest_specs.4.8"
 
     FileUtils.mkdir_p File.dirname(path)
 

test/rubygems/test_gem_commands_sources_command.rb

@@ -194,7 +194,7 @@ def test_execute_clear_all
     assert_equal expected, @ui.output
     assert_equal '', @ui.error
 
-    dir = File.join Gem.user_home, '.gem', 'specs'
+    dir = Gem.spec_cache_dir
     refute File.exist?(dir), 'cache dir removed'
   end
 

test/rubygems/test_gem_path_support.rb

@@ -64,4 +64,18 @@ def test_initialize_home_path
   def util_path
     ENV["GEM_PATH"].split(File::PATH_SEPARATOR)
   end
+
+  def test_initialize_spec
+    ENV["GEM_SPEC"] = nil
+    ps = Gem::PathSupport.new
+    assert_equal Gem.default_spec_cache_dir, ps.spec_cache_dir
+
+    ENV["GEM_SPEC"] = 'bar'
+    ps = Gem::PathSupport.new
+    assert_equal ENV["GEM_SPEC"], ps.spec_cache_dir
+    ENV["GEM_SPEC"] = File.join @tempdir, 'spec_cache'
+
+    ps = Gem::PathSupport.new "GEM_SPEC" => "foo"
+    assert_equal "foo", ps.spec_cache_dir
+  end
 end

test/rubygems/test_gem_source.rb

@@ -63,7 +63,7 @@ def test_api_uri_resolved_from_remote_fetcher
 
   def test_cache_dir_escapes_windows_paths
     uri = URI.parse("file:///C:/WINDOWS/Temp/gem_repo")
-    root = File.join Gem.user_home, '.gem', 'specs'
+    root = Gem.spec_cache_dir
     cache_dir = @source.cache_dir(uri).gsub(root, '')
     assert cache_dir !~ /:/, "#{cache_dir} should not contain a :"
   end
@@ -123,7 +123,7 @@ def test_load_specs
     expected = @released
     assert_equal expected, @source.load_specs(:released)
 
-    cache_dir = File.join Gem.user_home, '.gem', 'specs', 'gems.example.com%80'
+    cache_dir = File.join Gem.spec_cache_dir, 'gems.example.com%80'
     assert File.exist?(cache_dir), "#{cache_dir} does not exist"
 
     cache_file = File.join cache_dir, "specs.#{Gem.marshal_version}"
@@ -138,7 +138,7 @@ def test_load_specs_cached
     @fetcher.data["#{@gem_repo}latest_specs.#{Gem.marshal_version}"] =
       ' ' * Marshal.dump(@latest_specs).length
 
-    cache_dir = File.join Gem.user_home, '.gem', 'specs', 'gems.example.com%80'
+    cache_dir = File.join Gem.spec_cache_dir, 'gems.example.com%80'
 
     FileUtils.mkdir_p cache_dir
 
@@ -160,7 +160,7 @@ def test_load_specs_cached_empty
     @fetcher.data["#{@gem_repo}latest_specs.#{Gem.marshal_version}.gz"] =
           util_gzip(Marshal.dump(@latest_specs))
 
-    cache_dir = File.join Gem.user_home, '.gem', 'specs', 'gems.example.com%80'
+    cache_dir = File.join Gem.spec_cache_dir, 'gems.example.com%80'
 
     FileUtils.mkdir_p cache_dir