RUBY-991 handle Exceptions with non-String messages

lib/new_relic/noticed_error.rb

@@ -17,6 +17,14 @@ def initialize(path, data, exception, timestamp = Time.now)
       @message = (exception || '<no message>').to_s
     end
 
+    unless @message.is_a?(String)
+      # In pre-1.9.3, Exception.new({}).to_s.class != String
+      # That is, Exception#to_s may not return a String instance if one wasn't
+      # passed in upon creation of the Exception. So, try to generate a useful
+      # String representation of the exception message, falling back to failsafe
+      @message = String(@message.inspect) rescue '<unknown message type>'
+    end
+
     # clamp long messages to 4k so that we don't send a lot of
     # overhead across the wire
     @message = @message[0..4095] if @message.length > 4096

test/new_relic/noticed_error_test.rb

@@ -1,14 +1,24 @@
 require File.expand_path(File.join(File.dirname(__FILE__),'..','test_helper'))
 
 class NewRelic::Agent::NoticedErrorTest < Test::Unit::TestCase
+  def setup
+    @path = 'foo/bar/baz'
+    @params = { 'key' => 'val' }
+    @time = Time.now
+  end
+
   def test_to_collector_array
-    time = Time.now
-    error = NewRelic::NoticedError.new('path', {'key' => 'val'},
-                                       Exception.new('test exception'), time)
+    e = Exception.new('test exception')
+    error = NewRelic::NoticedError.new(@path, @params, e, @time)
     expected = [
-      (time.to_f * 1000).round, 'path', 'test exception', 'Exception',
-      {'key' => 'val'}
+      (@time.to_f * 1000).round, @path, 'test exception', 'Exception', @params
     ]
     assert_equal expected, error.to_collector_array
   end
+
+  def test_handles_non_string_exception_messages
+    e = Exception.new({ :non => :string })
+    error = NewRelic::NoticedError.new(@path, @params, e, @time)
+    assert_equal(String, error.message.class)
+  end
 end