Update regexes to bind to beginning and end of string

This ensures that multiline strings are properly matched in their
entirety.

lib/paperclip/interpolations.rb

@@ -48,7 +48,7 @@ module Paperclip
     # Returns the interpolated URL. Will raise an error if the url itself
     # contains ":url" to prevent infinite recursion. This interpolation
     # is used in the default :path to ease default specifications.
-    RIGHT_HERE = "#{__FILE__.gsub(%r{^\./}, "")}:#{__LINE__ + 3}"
+    RIGHT_HERE = "#{__FILE__.gsub(%r{\A\./}, "")}:#{__LINE__ + 3}"
     def url attachment, style_name
       raise Errors::InfiniteInterpolationError if caller.any?{|b| b.index(RIGHT_HERE) }
       attachment.url(style_name, :timestamp => false, :escape => false)
@@ -90,7 +90,7 @@ module Paperclip
 
     # Returns the basename of the file. e.g. "file" for "file.jpg"
     def basename attachment, style_name
-      attachment.original_filename.gsub(/#{Regexp.escape(File.extname(attachment.original_filename))}$/, "")
+      attachment.original_filename.gsub(/#{Regexp.escape(File.extname(attachment.original_filename))}\Z/, "")
     end
 
     # Returns the extension of the file. e.g. "jpg" for "file.jpg"
@@ -98,7 +98,7 @@ module Paperclip
     # of the actual extension.
     def extension attachment, style_name
       ((style = attachment.styles[style_name.to_s.to_sym]) && style[:format]) ||
-        File.extname(attachment.original_filename).gsub(/^\.+/, "")
+        File.extname(attachment.original_filename).gsub(/\A\.+/, "")
     end
 
     # Returns an extension based on the content type. e.g. "jpeg" for
@@ -128,7 +128,7 @@ module Paperclip
         # It's possible, though unlikely, that the mime type is not in the
         # database, so just use the part after the '/' in the mime type as the
         # extension.
-        %r{/([^/]*)$}.match(attachment.content_type)[1]
+        %r{/([^/]*)\Z}.match(attachment.content_type)[1]
       end
     end
 

lib/paperclip/io_adapters/data_uri_adapter.rb

 module Paperclip
   class DataUriAdapter < StringioAdapter
 
-    REGEXP = /^data:([-\w]+\/[-\w\+]+);base64,(.*)/m
+    REGEXP = /\Adata:([-\w]+\/[-\w\+]+);base64,(.*)/m
 
     def initialize(target_uri)
       @target_uri = target_uri

lib/paperclip/io_adapters/http_url_proxy_adapter.rb

 module Paperclip
   class HttpUrlProxyAdapter < UriAdapter
 
-    REGEXP = /^https?:\/\//
+    REGEXP = /\Ahttps?:\/\//
 
     def initialize(target)
       super(URI(target))

lib/paperclip/storage/fog.rb

@@ -43,8 +43,8 @@ module Paperclip
         end unless defined?(Fog)
 
         base.instance_eval do
-          unless @options[:url].to_s.match(/^:fog.*url$/)
-            @options[:path]  = @options[:path].gsub(/:url/, @options[:url]).gsub(/^:rails_root\/public\/system\//, '')
+          unless @options[:url].to_s.match(/\A:fog.*url\Z/)
+            @options[:path]  = @options[:path].gsub(/:url/, @options[:url]).gsub(/\A:rails_root\/public\/system\//, '')
             @options[:url]   = ':fog_public_url'
           end
           Paperclip.interpolates(:fog_public_url) do |attachment, style|
@@ -53,7 +53,7 @@ module Paperclip
         end
       end
 
-      AWS_BUCKET_SUBDOMAIN_RESTRICTON_REGEX = /^(?:[a-z]|\d(?!\d{0,2}(?:\.\d{1,3}){3}$))(?:[a-z0-9]|\.(?![\.\-])|\-(?![\.])){1,61}[a-z0-9]$/
+      AWS_BUCKET_SUBDOMAIN_RESTRICTON_REGEX = /\A(?:[a-z]|\d(?!\d{0,2}(?:\.\d{1,3}){3}\Z))(?:[a-z0-9]|\.(?![\.\-])|\-(?![\.])){1,61}[a-z0-9]\Z/
 
       def exists?(style = default_style)
         if original_filename

lib/paperclip/storage/s3.rb

@@ -149,8 +149,8 @@ module Paperclip
             @s3_server_side_encryption = @options[:s3_server_side_encryption].to_s.upcase
           end
 
-          unless @options[:url].to_s.match(/^:s3.*url$/) || @options[:url] == ":asset_host"
-            @options[:path] = @options[:path].gsub(/:url/, @options[:url]).gsub(/^:rails_root\/public\/system/, '')
+          unless @options[:url].to_s.match(/\A:s3.*url\Z/) || @options[:url] == ":asset_host"
+            @options[:path] = @options[:path].gsub(/:url/, @options[:url]).gsub(/\A:rails_root\/public\/system/, '')
             @options[:url]  = ":s3_path_url"
           end
           @options[:url] = @options[:url].inspect if @options[:url].is_a?(Symbol)
@@ -159,16 +159,16 @@ module Paperclip
         end
 
         Paperclip.interpolates(:s3_alias_url) do |attachment, style|
-          "#{attachment.s3_protocol(style, true)}//#{attachment.s3_host_alias}/#{attachment.path(style).gsub(%r{^/}, "")}"
+          "#{attachment.s3_protocol(style, true)}//#{attachment.s3_host_alias}/#{attachment.path(style).gsub(%r{\A/}, "")}"
         end unless Paperclip::Interpolations.respond_to? :s3_alias_url
         Paperclip.interpolates(:s3_path_url) do |attachment, style|
-          "#{attachment.s3_protocol(style, true)}//#{attachment.s3_host_name}/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
+          "#{attachment.s3_protocol(style, true)}//#{attachment.s3_host_name}/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{\A/}, "")}"
         end unless Paperclip::Interpolations.respond_to? :s3_path_url
         Paperclip.interpolates(:s3_domain_url) do |attachment, style|
-          "#{attachment.s3_protocol(style, true)}//#{attachment.bucket_name}.#{attachment.s3_host_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
+          "#{attachment.s3_protocol(style, true)}//#{attachment.bucket_name}.#{attachment.s3_host_name}/#{attachment.path(style).gsub(%r{\A/}, "")}"
         end unless Paperclip::Interpolations.respond_to? :s3_domain_url
         Paperclip.interpolates(:asset_host) do |attachment, style|
-          "#{attachment.path(style).gsub(%r{^/}, "")}"
+          "#{attachment.path(style).gsub(%r{\A/}, "")}"
         end unless Paperclip::Interpolations.respond_to? :asset_host
       end
 
@@ -244,7 +244,7 @@ module Paperclip
       end
 
       def s3_object style_name = default_style
-        s3_bucket.objects[path(style_name).sub(%r{^/},'')]
+        s3_bucket.objects[path(style_name).sub(%r{\A/},'')]
       end
 
       def using_http_proxy?
@@ -352,7 +352,7 @@ module Paperclip
         @queued_for_delete.each do |path|
           begin
             log("deleting #{path}")
-            s3_bucket.objects[path.sub(%r{^/},'')].delete
+            s3_bucket.objects[path.sub(%r{\A/},'')].delete
           rescue AWS::Errors::Base => e
             # Ignore this.
           end
@@ -397,10 +397,10 @@ module Paperclip
         http_headers = http_headers.call(instance) if http_headers.respond_to?(:call)
         http_headers.inject({}) do |headers,(name,value)|
           case name.to_s
-          when /^x-amz-meta-(.*)/i
+          when /\Ax-amz-meta-(.*)/i
             s3_metadata[$1.downcase] = value
           else
-            s3_headers[name.to_s.downcase.sub(/^x-amz-/,'').tr("-","_").to_sym] = value
+            s3_headers[name.to_s.downcase.sub(/\Ax-amz-/,'').tr("-","_").to_sym] = value
           end
         end
       end

lib/paperclip/tempfile_factory.rb

 module Paperclip
   class TempfileFactory
 
-    ILLEGAL_FILENAME_CHARACTERS = /^~/
+    ILLEGAL_FILENAME_CHARACTERS = /\A~/
 
     def generate(name)
       @name = name

lib/paperclip/validators.rb

@@ -30,7 +30,7 @@ module Paperclip
         options = attributes.extract_options!.dup
 
         Paperclip::Validators.constants.each do |constant|
-          if constant.to_s =~ /^Attachment(.+)Validator$/
+          if constant.to_s =~ /\AAttachment(.+)Validator\Z/
             validator_kind = $1.underscore.to_sym
 
             if options.has_key?(validator_kind)