Fix generation of wrong json string when field has multiple errors

1 files changed, 10 insertions, 0 deletions

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 99f47f2cbe..01ca540d28 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -167,6 +167,16 @@ module ActiveModel
     def as_json(options=nil)
       self
     end
+    
+    def encode_json(encoder)
+      errors = []
+      each_pair do |key, value|
+        value = value.first if value.size == 1
+        errors << "#{encoder.encode(key.to_s)}:#{encoder.encode(value, false)}"
+      end
+
+      "{#{errors * ','}}"
+    end
 
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same