[rubygems/rubygems] Fix binstubs sometimes not getting regenerated when --destdir is given

This was only working for gems also installed in the default gem home.

https://github.com/rubygems/rubygems/commit/47df02dbd9

lib/rubygems/commands/pristine_command.rb

@@ -57,7 +57,7 @@ class Gem::Commands::PristineCommand < Gem::Command
     end
 
     add_option("-i", "--install-dir DIR",
-               "Gem repository to get binstubs and plugins installed") do |value, options|
+               "Gem repository to get gems restored") do |value, options|
       options[:install_dir] = File.expand_path(value)
     end
 
@@ -103,21 +103,25 @@ extensions will be restored.
   end
 
   def execute
+    install_dir = options[:install_dir]
+
+    specification_record = install_dir ? Gem::SpecificationRecord.from_path(install_dir) : Gem::Specification.specification_record
+
     specs = if options[:all]
-      Gem::Specification.map
+      specification_record.map
 
     # `--extensions` must be explicitly given to pristine only gems
     # with extensions.
     elsif options[:extensions_set] &&
           options[:extensions] && options[:args].empty?
-      Gem::Specification.select do |spec|
+      specification_record.select do |spec|
         spec.extensions && !spec.extensions.empty?
       end
     elsif options[:only_missing_extensions]
-      Gem::Specification.select(&:missing_extensions?)
+      specification_record.select(&:missing_extensions?)
     else
       get_all_gem_names.sort.map do |gem_name|
-        Gem::Specification.find_all_by_name(gem_name, options[:version]).reverse
+        specification_record.find_all_by_name(gem_name, options[:version]).reverse
       end.flatten
     end
 
@@ -176,7 +180,6 @@ extensions will be restored.
         end
 
       bin_dir = options[:bin_dir] if options[:bin_dir]
-      install_dir = options[:install_dir] if options[:install_dir]
 
       installer_options = {
         wrappers: true,

lib/rubygems/commands/setup_command.rb

@@ -585,6 +585,8 @@ abort "#{deprecation_message}"
 
     args = %w[--all --only-executables --silent]
     args << "--bindir=#{bindir}"
+    args << "--install-dir=#{default_dir}"
+
     if options[:env_shebang]
       args << "--env-shebang"
     end

lib/rubygems/installer.rb

@@ -344,7 +344,7 @@ class Gem::Installer
 
     say spec.post_install_message if options[:post_install_message] && !spec.post_install_message.nil?
 
-    Gem::Specification.add_spec(spec)
+    Gem::Specification.add_spec(spec) unless @install_dir
 
     load_plugin
 

lib/rubygems/specification.rb

@@ -925,31 +925,15 @@ class Gem::Specification < Gem::BasicSpecification
   # Enumerate every known spec.  See ::dirs= and ::add_spec to set the list of
   # specs.
 
-  def self.each
-    return enum_for(:each) unless block_given?
-
-    _all.each do |x|
-      yield x
-    end
+  def self.each(&block)
+    specification_record.each(&block)
   end
 
   ##
   # Returns every spec that matches +name+ and optional +requirements+.
 
   def self.find_all_by_name(name, *requirements)
-    req = Gem::Requirement.create(*requirements)
-    env_req = Gem.env_requirement(name)
-
-    matches = stubs_for(name).find_all do |spec|
-      req.satisfied_by?(spec.version) && env_req.satisfied_by?(spec.version)
-    end.map(&:to_spec)
-
-    if name == "bundler" && !req.specific?
-      require_relative "bundler_version_finder"
-      Gem::BundlerVersionFinder.prioritize!(matches)
-    end
-
-    matches
+    specification_record.find_all_by_name(name, *requirements)
   end
 
   ##

lib/rubygems/specification_record.rb

@@ -111,6 +111,38 @@ module Gem
       all.map(&:full_name)
     end
 
+    include Enumerable
+
+    ##
+    # Enumerate every known spec.
+
+    def each
+      return enum_for(:each) unless block_given?
+
+      all.each do |x|
+        yield x
+      end
+    end
+
+    ##
+    # Returns every spec in the record that matches +name+ and optional +requirements+.
+
+    def find_all_by_name(name, *requirements)
+      req = Gem::Requirement.create(*requirements)
+      env_req = Gem.env_requirement(name)
+
+      matches = stubs_for(name).find_all do |spec|
+        req.satisfied_by?(spec.version) && env_req.satisfied_by?(spec.version)
+      end.map(&:to_spec)
+
+      if name == "bundler" && !req.specific?
+        require_relative "bundler_version_finder"
+        Gem::BundlerVersionFinder.prioritize!(matches)
+      end
+
+      matches
+    end
+
     ##
     # Return the best specification in the record that contains the file matching +path+.
 

test/rubygems/test_gem_commands_setup_command.rb

@@ -159,6 +159,23 @@ class TestGemCommandsSetupCommand < Gem::TestCase
     end
   end
 
+  def test_destdir_flag_regenerates_binstubs
+    # install to destdir
+    destdir = File.join(@tempdir, "foo")
+    gem_bin_path = gem_install "destdir-only-gem", install_dir: destdir
+
+    # change binstub manually
+    write_file gem_bin_path do |io|
+      io.puts "I changed it!"
+    end
+
+    @cmd.options[:destdir] = destdir
+    @cmd.options[:prefix] = "/"
+    @cmd.execute
+
+    assert_match(/\A#!/, File.read(gem_bin_path))
+  end
+
   def test_files_in
     assert_equal %w[rubygems.rb rubygems/requirement.rb rubygems/ssl_certs/rubygems.org/foo.pem],
                  @cmd.files_in("lib").sort
@@ -412,7 +429,7 @@ class TestGemCommandsSetupCommand < Gem::TestCase
     end
   end
 
-  def gem_install(name)
+  def gem_install(name, **options)
     gem = util_spec name do |s|
       s.executables = [name]
       s.files = %W[bin/#{name}]
@@ -420,8 +437,8 @@ class TestGemCommandsSetupCommand < Gem::TestCase
     write_file File.join @tempdir, "bin", name do |f|
       f.puts "#!/usr/bin/ruby"
     end
-    install_gem gem
-    File.join @gemhome, "bin", name
+    install_gem gem, **options
+    File.join options[:install_dir] || @gemhome, "bin", name
   end
 
   def gem_install_with_plugin(name)