Merge pull request #2285 from eugenk/2284-handle_circular_error_causes

Handle circular error causes

lib/sidekiq/middleware/server/retry_jobs.rb

@@ -188,12 +188,16 @@ module Sidekiq
           end
         end
 
-        def exception_caused_by_shutdown?(e)
+        def exception_caused_by_shutdown?(e, checked_causes = [])
           # In Ruby 2.1.0 only, check if exception is a result of shutdown.
           return false unless defined?(e.cause)
 
+          # Handle circular causes
+          checked_causes << e.object_id
+          return false if checked_causes.include?(e.cause.object_id)
+
           e.cause.instance_of?(Sidekiq::Shutdown) ||
-            exception_caused_by_shutdown?(e.cause)
+            exception_caused_by_shutdown?(e.cause, checked_causes)
         end
 
       end

test/test_retry.rb

@@ -328,6 +328,46 @@ class TestRetry < Sidekiq::Test
                      File.read(@tmp_log_path), 'Log entry missing for sidekiq_retry_in')
       end
     end
+
+    describe 'handles errors withouth cause' do
+      before do
+        @error = nil
+        begin
+          raise ::StandardError, 'Error'
+        rescue ::StandardError => e
+          @error = e
+        end
+      end
+
+      it "does not recurse infinitely checking if it's a shutdown" do
+        assert(!Sidekiq::Middleware::Server::RetryJobs.new.send(
+          :exception_caused_by_shutdown?, @error))
+      end
+    end
+
+    describe 'handles errors with circular causes' do
+      before do
+        @error = nil
+        begin
+          begin
+            raise ::StandardError, 'Error 1'
+          rescue ::StandardError => e1
+            begin
+              raise ::StandardError, 'Error 2'
+            rescue ::StandardError => e2
+              raise e1
+            end
+          end
+        rescue ::StandardError => e
+          @error = e
+        end
+      end
+
+      it "does not recurse infinitely checking if it's a shutdown" do
+        assert(!Sidekiq::Middleware::Server::RetryJobs.new.send(
+          :exception_caused_by_shutdown?, @error))
+      end
+    end
   end
 
 end