Merge branch 'master' into nested_has_many_through

Conflicts:
	activerecord/CHANGELOG
	activerecord/lib/active_record/association_preload.rb
	activerecord/lib/active_record/associations.rb
	activerecord/lib/active_record/associations/class_methods/join_dependency.rb
	activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
	activerecord/lib/active_record/associations/has_many_association.rb
	activerecord/lib/active_record/associations/has_many_through_association.rb
	activerecord/lib/active_record/associations/has_one_association.rb
	activerecord/lib/active_record/associations/has_one_through_association.rb
	activerecord/lib/active_record/associations/through_association_scope.rb
	activerecord/lib/active_record/reflection.rb
	activerecord/test/cases/associations/has_many_through_associations_test.rb
	activerecord/test/cases/associations/has_one_through_associations_test.rb
	activerecord/test/cases/reflection_test.rb
	activerecord/test/cases/relations_test.rb
	activerecord/test/fixtures/memberships.yml
	activerecord/test/models/categorization.rb
	activerecord/test/models/category.rb
	activerecord/test/models/member.rb
	activerecord/test/models/reference.rb
	activerecord/test/models/tagging.rb

1 files changed, 28 insertions, 7 deletions

diff --git a/activesupport/lib/active_support/json/backends/yaml.rb b/activesupport/lib/active_support/json/backends/yaml.rb
index 4cb9d01077..077eda548a 100644
--- a/activesupport/lib/active_support/json/backends/yaml.rb
+++ b/activesupport/lib/active_support/json/backends/yaml.rb
@@ -7,14 +7,21 @@ module ActiveSupport
         ParseError = ::StandardError
         extend self
 
+        EXCEPTIONS = [::ArgumentError] # :nodoc:
+        begin
+          require 'psych'
+          EXCEPTIONS << Psych::SyntaxError
+        rescue LoadError
+        end
+
         # Parses a JSON string or IO and converts it into an object
         def decode(json)
           if json.respond_to?(:read)
             json = json.read
           end
           YAML.load(convert_json_to_yaml(json))
-        rescue ArgumentError
-          raise ParseError, "Invalid JSON string"
+        rescue *EXCEPTIONS => e
+          raise ParseError, "Invalid JSON string: '%s'" % json
         end
 
         protected
@@ -29,10 +36,10 @@ module ActiveSupport
                   quoting = char
                   pos = scanner.pos
                 elsif quoting == char
-                  if json[pos..scanner.pos-2] =~ DATE_REGEX
+                  if valid_date?(json[pos..scanner.pos-2])
                     # found a date, track the exact positions of the quotes so we can
                     # overwrite them with spaces later.
-                    times << pos << scanner.pos
+                    times << pos
                   end
                   quoting = false
                 end
@@ -47,7 +54,9 @@ module ActiveSupport
               json.gsub(/\\([\\\/]|u[[:xdigit:]]{4})/) do
                 ustr = $1
                 if ustr.start_with?('u')
-                  [ustr[1..-1].to_i(16)].pack("U")
+                  char = [ustr[1..-1].to_i(16)].pack("U")
+                  # "\n" needs extra escaping due to yaml formatting
+                  char == "\n" ? "\\n" : char
                 elsif ustr == '\\'
                   '\\\\'
                 else
@@ -63,12 +72,14 @@ module ActiveSupport
                 chunk = scanner.peek(right_pos[i] - scanner.pos + 1)
                 # overwrite the quotes found around the dates with spaces
                 while times.size > 0 && times[0] <= right_pos[i]
-                  chunk[times.shift - scanner.pos - 1] = ' '
+                  chunk.insert(times.shift - scanner.pos - 1, '! ')
                 end
                 chunk.gsub!(/\\([\\\/]|u[[:xdigit:]]{4})/) do
                   ustr = $1
                   if ustr.start_with?('u')
-                    [ustr[1..-1].to_i(16)].pack("U")
+                    char = [ustr[1..-1].to_i(16)].pack("U")
+                    # "\n" needs extra escaping due to yaml formatting
+                    char == "\n" ? "\\n" : char
                   elsif ustr == '\\'
                     '\\\\'
                   else
@@ -83,6 +94,16 @@ module ActiveSupport
               output
             end
           end
+
+        private
+          def valid_date?(date_string)
+            begin
+              date_string =~ DATE_REGEX && DateTime.parse(date_string)
+            rescue ArgumentError
+              false
+            end
+          end
+
       end
     end
   end