[rubygems/rubygems] Exclude Bundler from missing locked dependencies check

Bundler is special since it's not actually locked in the lockfile as a
regular gem (only via `BUNDLED WITH`). So exclude it from that check.

https://github.com/rubygems/rubygems/commit/9f1756ec47

2 files changed, 11 insertions, 1 deletions

diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index 1970782d55..e043630c2d 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -700,7 +700,7 @@ module Bundler
       return if @dependency_changes
 
       current_dependencies.find do |d|
-        @locked_specs[d.name].empty?
+        @locked_specs[d.name].empty? && d.name != "bundler"
       end&.name
     end
 
diff --git a/spec/bundler/runtime/setup_spec.rb b/spec/bundler/runtime/setup_spec.rb
index 713cab2124..75f2a62868 100644
--- a/spec/bundler/runtime/setup_spec.rb
+++ b/spec/bundler/runtime/setup_spec.rb
@@ -639,6 +639,16 @@ RSpec.describe "Bundler.setup" do
       expect(err).to be_empty
     end
 
+    it "doesn't fail in frozen mode when bundler is a Gemfile dependency" do
+      install_gemfile <<~G
+        source "#{file_uri_for(gem_repo4)}"
+        gem "bundler"
+      G
+
+      bundle "install --verbose", :env => { "BUNDLE_FROZEN" => "true" }
+      expect(err).to be_empty
+    end
+
     it "doesn't re-resolve when deleting dependencies" do
       install_gemfile <<-G
         source "#{file_uri_for(gem_repo1)}"