Compare sources using source's root

When doing the following:

    expand(other.original_path)

inside a Bundler::Source::Path instance, the `@root_path` from the
instance that is having eql? called on it, the other instance's
root_path. This, in obscure cases, can cause a bug when you are doing an
nested eval_gemfile or other calls when comparing the lockfile's locked
path sources to the Bundler.definition's path sources.

Creating the expanded_original_path method allows a public interface to
be made available (and doesn't mess with any exiting functionality) that
allows comparing the source path of one Source::Path's expand_path to
another, where each uses their own root_path to resolve their full path,
instead of sharing the base one and causing edge case bugs

3 files changed, 43 insertions, 1 deletions

diff --git a/lib/bundler/source/path.rb b/lib/bundler/source/path.rb
index 99808d2ef2..b13f971858 100644
--- a/lib/bundler/source/path.rb
+++ b/lib/bundler/source/path.rb
@@ -65,7 +65,7 @@ module Bundler
 
       def eql?(other)
         return unless other.class == self.class
-        expand(@original_path) == expand(other.original_path) &&
+        expanded_original_path == other.expanded_original_path &&
           version == other.version
       end
 
@@ -119,6 +119,10 @@ module Bundler
         instance_of?(Path)
       end
 
+      def expanded_original_path
+        @expanded_original_path ||= expand(original_path)
+      end
+
     private
 
       def expanded_path
diff --git a/spec/bundler/source/path_spec.rb b/spec/bundler/source/path_spec.rb
new file mode 100644
index 0000000000..1d13e03ec1
--- /dev/null
+++ b/spec/bundler/source/path_spec.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+RSpec.describe Bundler::Source::Path do
+  before do
+    allow(Bundler).to receive(:root) { Pathname.new("root") }
+  end
+
+  describe "#eql?" do
+    subject { described_class.new("path" => "gems/a") }
+
+    context "with two equivalent relative paths from different roots" do
+      let(:a_gem_opts) { { "path" => "../gems/a", "root_path" => Bundler.root.join("nested") } }
+      let(:a_gem)      { described_class.new a_gem_opts }
+
+      it "returns true" do
+        expect(subject).to eq a_gem
+      end
+    end
+
+    context "with the same (but not equivalent) relative path from different roots" do
+      subject { described_class.new("path" => "gems/a") }
+
+      let(:a_gem_opts) { { "path" => "gems/a", "root_path" => Bundler.root.join("nested") } }
+      let(:a_gem)      { described_class.new a_gem_opts }
+
+      it "returns false" do
+        expect(subject).to_not eq a_gem
+      end
+    end
+  end
+end
diff --git a/spec/install/gemfile/eval_gemfile_spec.rb b/spec/install/gemfile/eval_gemfile_spec.rb
index f3f9cb6444..0588bea3da 100644
--- a/spec/install/gemfile/eval_gemfile_spec.rb
+++ b/spec/install/gemfile/eval_gemfile_spec.rb
@@ -41,6 +41,13 @@ RSpec.describe "bundle install with gemfile that uses eval_gemfile" do
       bundle! :install
       expect(the_bundle).to include_gem("a 1.0")
     end
+
+    # Make sure that we are properly comparing path based gems between the
+    # parsed lockfile and the evaluated gemfile.
+    it "bundles with --deployment" do
+      bundle! :install
+      bundle! "install --deployment"
+    end
   end
 
   context "Gemfile uses gemspec paths after eval-ing a Gemfile" do