Merge #6805

6805: [Plugin] Ignore the deployment setting r=colby-swandale a=segiddins

### What was the end-user problem that led to this PR?

The problem was installing a new plugin in deployment mode would fail with a suggestion the lock file was corrupted, when it installed fine without deployment mode.

Fixes #6795.

### What was your diagnosis of the problem?

My diagnosis was deployment mode was interfering with installing a new plugin.

### What is your fix for the problem, implemented in this PR?

My fix overrides the deployment and frozen settings when creating the plugin Definition.

### Why did you choose this fix out of the possible options?

I chose this fix because having a "frozen" plugin bundle makes no sense, since plugins aren't written to the lockfile.

Co-authored-by: Samuel Giddins <segiddins@segiddins.me>
(cherry picked from commit 07d22ae)

lib/bundler/plugin.rb

@@ -53,20 +53,22 @@ def install(names, options)
     # @param [Pathname] gemfile path
     # @param [Proc] block that can be evaluated for (inline) Gemfile
     def gemfile_install(gemfile = nil, &inline)
-      builder = DSL.new
-      if block_given?
-        builder.instance_eval(&inline)
-      else
-        builder.eval_gemfile(gemfile)
-      end
-      definition = builder.to_definition(nil, true)
+      Bundler.settings.temporary(:frozen => false, :deployment => false) do
+        builder = DSL.new
+        if block_given?
+          builder.instance_eval(&inline)
+        else
+          builder.eval_gemfile(gemfile)
+        end
+        definition = builder.to_definition(nil, true)
 
-      return if definition.dependencies.empty?
+        return if definition.dependencies.empty?
 
-      plugins = definition.dependencies.map(&:name).reject {|p| index.installed? p }
-      installed_specs = Installer.new.install_definition(definition)
+        plugins = definition.dependencies.map(&:name).reject {|p| index.installed? p }
+        installed_specs = Installer.new.install_definition(definition)
 
-      save_plugins plugins, installed_specs, builder.inferred_plugins
+        save_plugins plugins, installed_specs, builder.inferred_plugins
+      end
     rescue RuntimeError => e
       unless e.is_a?(GemfileError)
         Bundler.ui.error "Failed to install plugin: #{e.message}\n  #{e.backtrace[0]}"

spec/plugins/install_spec.rb

@@ -173,6 +173,28 @@ def exec(command, args)
       expect(out).to include("Installed plugin ga-plugin")
       plugin_should_be_installed("ga-plugin")
     end
+
+    context "in deployment mode" do
+      it "installs plugins" do
+        install_gemfile! <<-G
+          source 'file://#{gem_repo2}'
+          gem 'rack', "1.0.0"
+        G
+
+        install_gemfile! <<-G, forgotten_command_line_options(:deployment => true)
+          source 'file://#{gem_repo2}'
+          plugin 'foo'
+          gem 'rack', "1.0.0"
+        G
+
+        expect(out).to include("Installed plugin foo")
+
+        expect(out).to include("Bundle complete!")
+
+        expect(the_bundle).to include_gems("rack 1.0.0")
+        plugin_should_be_installed("foo")
+      end
+    end
   end
 
   context "inline gemfiles" do