Auto merge of #5106 - bundler:seg-public-gem, r=indirect

[RubygemsIntegration] Temporarily make #gem public again

Closes #5102

\c @indirect @schneems

(cherry picked from commit 90b99f2)

Author: homu

lib/bundler/rubygems_integration.rb

@@ -348,6 +348,10 @@ def replace_gem(specs)
 
           true
         end
+
+        # TODO: delete this in 2.0, it's a backwards compatibility shim
+        # see https://github.com/bundler/bundler/issues/5102
+        kernel_class.send(:public, :gem)
       end
     end
 

spec/runtime/setup_spec.rb

@@ -1094,4 +1094,19 @@ def lock_with(ruby_version = nil)
       expect(post_bundler).to match(/\d+\.\d+\.\d+/)
     end
   end
+
+  describe "after setup" do
+    it "allows calling #gem on random objects" do
+      install_gemfile <<-G
+        source "file:#{gem_repo1}"
+        gem "rack"
+      G
+      ruby! <<-RUBY
+        require "bundler/setup"
+        Object.new.gem "rack"
+        puts Gem.loaded_specs["rack"].full_name
+      RUBY
+      expect(out).to eq("rack-1.0.0")
+    end
+  end
 end