Cleanse error message bytes, fixes #1705

Changes.md

@@ -1,6 +1,7 @@
 3.2.3
 -----------
 
+- Clean invalid bytes from error message before converting to JSON (requires Ruby 2.1+) [#1705]
 - Add queues list for each process to the Busy page. [davetoxa, #1897]
 - Fix for crash caused by empty config file. [jordan0day, #1901]
 - Add Rails Worker generator, `rails g sidekiq:worker User` will create `app/workers/user_worker.rb`. [seuros, #1909]

lib/sidekiq/middleware/server/retry_jobs.rb

@@ -86,7 +86,16 @@ module Sidekiq
           else
             queue
           end
-          msg['error_message'] = e.message[0..10_000]
+
+          # App code can stuff all sorts of crazy binary data into the error message
+          # that won't convert to JSON.
+          m = e.message[0..10_000]
+          if m.respond_to?(:scrub!)
+            m.force_encoding("utf-8")
+            m.scrub!
+          end
+
+          msg['error_message'] = m
           msg['error_class'] = e.class.name
           count = if msg['retry_count']
             msg['retried_at'] = Time.now.to_f

test/test_retry.rb

@@ -50,6 +50,22 @@ class TestRetry < Sidekiq::Test
       @redis.verify
     end
 
+    it 'handles zany characters in error message, #1705' do
+      @redis.expect :zadd, 1, ['retry', String, String]
+      msg = { 'class' => 'Bob', 'args' => [1,2,'foo'], 'retry' => 2 }
+      msg2 = msg.dup
+      handler = Sidekiq::Middleware::Server::RetryJobs.new
+      assert_raises RuntimeError do
+        handler.call(worker, msg2, 'default') do
+          raise "kerblammo! #{195.chr}"
+        end
+      end
+      msg2.delete('failed_at')
+      assert_equal({"class"=>"Bob", "args"=>[1, 2, "foo"], "retry"=>2, "queue"=>"default", "error_message"=>"kerblammo! <20>", "error_class"=>"RuntimeError", "retry_count"=>0}, msg2)
+      @redis.verify
+    end
+
+
     it 'allows a max_retries option in initializer' do
       max_retries = 7
       1.upto(max_retries) do