[ruby/rubygems] Make the Bundler logger thread safe:

- The Logger is not thread safe when calling `with_level`.
  This now becomes problematic because we are using multiple
  threads during the resolution phase in order to fetch git gems.

https://github.com/ruby/rubygems/commit/380653ae74

1 files changed, 28 insertions, 0 deletions

diff --git a/spec/bundler/bundler/ui/shell_spec.rb b/spec/bundler/bundler/ui/shell_spec.rb
index 422c850a65..83f147191e 100644
--- a/spec/bundler/bundler/ui/shell_spec.rb
+++ b/spec/bundler/bundler/ui/shell_spec.rb
@@ -81,4 +81,32 @@ RSpec.describe Bundler::UI::Shell do
       end
     end
   end
+
+  describe "threads" do
+    it "is thread safe when using with_level" do
+      stop_thr1 = false
+      stop_thr2 = false
+
+      expect(subject.level).to eq("debug")
+
+      thr1 = Thread.new do
+        subject.silence do
+          sleep(0.1) until stop_thr1
+        end
+
+        stop_thr2 = true
+      end
+
+      thr2 = Thread.new do
+        subject.silence do
+          stop_thr1 = true
+          sleep(0.1) until stop_thr2
+        end
+      end
+
+      [thr1, thr2].each(&:join)
+
+      expect(subject.level).to eq("debug")
+    end
+  end
 end