1 files changed, 7 insertions, 1 deletions
diff --git a/activesupport/lib/active_support/core_ext/object/blank.rb b/activesupport/lib/active_support/core_ext/object/blank.rb
index 8221dc4abe..d060ac04d8 100644
--- a/activesupport/lib/active_support/core_ext/object/blank.rb
+++ b/activesupport/lib/active_support/core_ext/object/blank.rb
@@ -1,3 +1,5 @@
+# encoding: utf-8
+
 class Object
   # An object is blank if it's false, empty, or a whitespace string.
   # For example, "", "   ", +nil+, [], and {} are all blank.
@@ -86,14 +88,18 @@ class Hash
 end
 
 class String
+  # 0x3000: fullwidth whitespace
+  NON_WHITESPACE_REGEXP = %r![^\s#{[0x3000].pack("U")}]!
+
   # A string is blank if it's empty or contains whitespaces only:
   #
   #   "".blank?                 # => true
   #   "   ".blank?              # => true
+  #   "　".blank?               # => true
   #   " something here ".blank? # => false
   #
   def blank?
-    self !~ /\S/
+    self !~ NON_WHITESPACE_REGEXP
   end
 end