1 files changed, 13 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..fe27f45295 100644
--- a/activesupport/lib/active_support/core_ext/object/blank.rb
+++ b/activesupport/lib/active_support/core_ext/object/blank.rb
@@ -1,3 +1,6 @@
+# encoding: utf-8
+require 'active_support/core_ext/string/encoding'
+
 class Object
   # An object is blank if it's false, empty, or a whitespace string.
   # For example, "", "   ", +nil+, [], and {} are all blank.
@@ -86,14 +89,23 @@ 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/
+    # 1.8 does not takes [:space:] properly
+    if encoding_aware?
+      self !~ /[^[:space:]]/
+    else
+      self !~ NON_WHITESPACE_REGEXP
+    end
   end
 end