1 files changed, 13 insertions, 4 deletions
diff --git a/activesupport/lib/active_support/multibyte/chars.rb b/activesupport/lib/active_support/multibyte/chars.rb
index 3c0cf9f137..707cf200b5 100644
--- a/activesupport/lib/active_support/multibyte/chars.rb
+++ b/activesupport/lib/active_support/multibyte/chars.rb
@@ -1,4 +1,3 @@
-# encoding: utf-8
 require 'active_support/json'
 require 'active_support/core_ext/string/access'
 require 'active_support/core_ext/string/behavior'
@@ -86,10 +85,20 @@ module ActiveSupport #:nodoc:
         @wrapped_string.split(*args).map { |i| self.class.new(i) }
       end
 
-      # Works like like <tt>String#slice!</tt>, but returns an instance of
-      # Chars, or nil if the string was not modified.
+      # Works like <tt>String#slice!</tt>, but returns an instance of
+      # Chars, or nil if the string was not modified. The string will not be
+      # modified if the range given is out of bounds
+      #
+      #   string = 'Welcome'
+      #   string.mb_chars.slice!(3)    # => #<ActiveSupport::Multibyte::Chars:0x000000038109b8 @wrapped_string="c">
+      #   string # => 'Welome'
+      #   string.mb_chars.slice!(0..3) # => #<ActiveSupport::Multibyte::Chars:0x00000002eb80a0 @wrapped_string="Welo">
+      #   string # => 'me'
       def slice!(*args)
-        chars(@wrapped_string.slice!(*args))
+        string_sliced = @wrapped_string.slice!(*args)
+        if string_sliced
+          chars(string_sliced)
+        end
       end
 
       # Reverses all characters in the string.