Make relativeness of config a feature flag

5 files changed, 47 insertions, 10 deletions

diff --git a/lib/bundler.rb b/lib/bundler.rb
index 9cf6924bda..c264334adb 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -286,7 +286,13 @@ module Bundler
         end
       end
 
-      current_config_root.join(app_config || ".bundle")
+      config_root = if Bundler.feature_flag.config_relative_to_cwd?
+        current_config_root
+      else
+        app_config_root
+      end
+
+      config_root.join(app_config || ".bundle")
     end
 
     def app_cache(custom_path = nil)
diff --git a/lib/bundler/cli.rb b/lib/bundler/cli.rb
index 6f7ff90dc2..aef434f569 100644
--- a/lib/bundler/cli.rb
+++ b/lib/bundler/cli.rb
@@ -54,10 +54,14 @@ module Bundler
     def initialize(*args)
       super
 
-      custom_gemfile = options[:gemfile] || Bundler.settings[:gemfile]
-      if custom_gemfile && !custom_gemfile.empty?
-        Bundler::SharedHelpers.set_env "BUNDLE_GEMFILE", File.expand_path(custom_gemfile)
-        Bundler.reset_paths!
+      if Bundler.feature_flag.config_relative_to_cwd?
+        Bundler.settings.set_command_option_if_given :gemfile, options[:gemfile]
+      else
+        custom_gemfile = options[:gemfile] || Bundler.settings[:gemfile]
+        if custom_gemfile && !custom_gemfile.empty?
+          Bundler::SharedHelpers.set_env "BUNDLE_GEMFILE", File.expand_path(custom_gemfile)
+          Bundler.reset_paths!
+        end
       end
 
       Bundler.settings.set_command_option_if_given :retry, options[:retry]
diff --git a/lib/bundler/feature_flag.rb b/lib/bundler/feature_flag.rb
index 01739ec4aa..0e4a0e1217 100644
--- a/lib/bundler/feature_flag.rb
+++ b/lib/bundler/feature_flag.rb
@@ -25,6 +25,15 @@ module Bundler
     end
     private_class_method :settings_method
 
+    def self.env_flag(name, &default)
+      define_method(:"#{name}?") do
+        value = ENV["BUNDLE_#{name.to_s.upcase}"]
+        value = instance_eval(&default) if value.nil?
+        value
+      end
+    end
+    private_class_method :env_flag
+
     (1..10).each {|v| define_method("bundler_#{v}_mode?") { major_version >= v } }
 
     settings_flag(:allow_bundler_dependency_conflicts) { bundler_3_mode? }
@@ -51,6 +60,8 @@ module Bundler
 
     settings_option(:default_cli_command) { bundler_3_mode? ? :cli_help : :install }
 
+    env_flag(:config_relative_to_cwd) { bundler_3_mode? }
+
     def initialize(bundler_version)
       @bundler_version = Gem::Version.create(bundler_version)
     end
diff --git a/lib/bundler/shared_helpers.rb b/lib/bundler/shared_helpers.rb
index e8f9bfd610..960a935cd3 100644
--- a/lib/bundler/shared_helpers.rb
+++ b/lib/bundler/shared_helpers.rb
@@ -238,7 +238,11 @@ module Bundler
 
     def find_gemfile
       require_relative "../bundler"
-      given = Bundler.settings[:gemfile]
+      given = if Bundler.feature_flag.config_relative_to_cwd?
+        Bundler.settings[:gemfile]
+      else
+        ENV["BUNDLE_GEMFILE"]
+      end
       return given if given && !given.empty?
       find_file(*gemfile_names)
     end
diff --git a/spec/commands/config_spec.rb b/spec/commands/config_spec.rb
index 11fdd1ac78..26e75bbfd6 100644
--- a/spec/commands/config_spec.rb
+++ b/spec/commands/config_spec.rb
@@ -53,7 +53,19 @@ RSpec.describe ".bundle/config" do
       expect(the_bundle).to include_gems "rack 1.0.0"
     end
 
-    it "can provide a relative path with the environment variable" do
+    it "can provide a relative path with the environment variable, and generates config relative to the Gemfile", :bundler => "< 3" do
+      FileUtils.mkdir_p bundled_app("omg")
+
+      ENV["BUNDLE_APP_CONFIG"] = "../foo"
+      bundle "config set --local path vendor/bundle", :dir => bundled_app("omg")
+      bundle "install", :dir => bundled_app("omg")
+
+      expect(bundled_app(".bundle")).not_to exist
+      expect(bundled_app("../foo/config")).to exist
+      expect(the_bundle).to include_gems "rack 1.0.0"
+    end
+
+    it "can provide a relative path with the environment variable, and generates config relative to the cwd", :bundler => "3" do
       FileUtils.mkdir_p bundled_app("omg")
 
       ENV["BUNDLE_APP_CONFIG"] = "../foo"
@@ -65,7 +77,7 @@ RSpec.describe ".bundle/config" do
       expect(the_bundle).to include_gems "rack 1.0.0", :dir => bundled_app("omg")
     end
 
-    it "is relative to the pwd and not to the gemfile" do
+    it "is relative to the pwd and not to the gemfile", :bundler => "3" do
       FileUtils.mkdir_p bundled_app("omg/gmo")
 
       gemfile bundled_app("omg/gmo/AnotherGemfile"), <<-G
@@ -78,7 +90,7 @@ RSpec.describe ".bundle/config" do
       expect(bundled_app("omg/.bundle")).to exist
     end
 
-    it "uses the first existing local config from the pwd and not from the gemfile" do
+    it "uses the first existing local config from the pwd and not from the gemfile", :bundler => "3" do
       bundle "install"
 
       FileUtils.mkdir_p bundled_app("omg/gmo")
@@ -534,7 +546,7 @@ RSpec.describe "setting gemfile via config" do
       expect(out).to include("NotGemfile")
     end
 
-    it "gets used when requiring bundler/setup" do
+    it "gets used when requiring bundler/setup", :bundler => "3" do
       bundle :install
       code = "puts $LOAD_PATH.count {|path| path =~ /rack/} == 1"