+ Rewrote tests as specs. Ruby1.9 compatible escape code.

lib/net/ldap/filter.rb

@@ -1,3 +1,4 @@
+# Encoding: UTF-8
 # Copyright (C) 2006 by Francis Cianfrocca and other contributors. All
 # Rights Reserved.
 #
@@ -243,10 +244,28 @@ class Net::LDAP::Filter
     alias_method :present, :present?
     alias_method :pres, :present?
 
+    # http://tools.ietf.org/html/rfc4515 lists these exceptions from UTF1
+    # charset for filters. All of the following must be escaped in any normal
+    # string using a single backslash ('\') as escape. 
+    #
+    ESCAPES = {
+      '!' => '21', # EXCLAMATION    = %x21 ; exclamation mark ("!")
+      '&' => '26', # AMPERSAND      = %x26 ; ampersand (or AND symbol) ("&")
+      '*' => '2A', # ASTERISK       = %x2A ; asterisk ("*")
+      ':' => '3A', # COLON          = %x3A ; colon (":")
+      '|' => '7C', # VERTBAR        = %x7C ; vertical bar (or pipe) ("|")
+      '~' => '7E', # TILDE          = %x7E ; tilde ("~")
+    }
+    # Compiled character class regexp using the keys from the above hash. 
+    ESCAPE_RE = Regexp.new(
+      "[" + 
+      ESCAPES.keys.map { |e| Regexp.escape(e) }.join + 
+      "]")
+
     ##
     # Escape a string for use in an LDAP filter
     def escape(string)
-      string.gsub(/[\*\(\)\\\0]/) {|s| sprintf("\\%02x", s[0]) } 
+      string.gsub(ESCAPE_RE) { |char| "\\" + ESCAPES[char] }
     end
 
     ##