! A proper fix for the error I've found yesterday.

We should further look for empty rescue statements, as they may
sometimes catch stuff that we don't want to be caught.

lib/net/ldap.rb

@@ -1,6 +1,5 @@
 require 'openssl'
 require 'ostruct'
-
 require 'socket'
 
 require 'net/ber'
@@ -1122,8 +1121,10 @@ module Net
       def initialize server
         begin
           @conn = TCPSocket.new( server[:host], server[:port] )
-        rescue
+        rescue SocketError
-          raise LdapError.new( "no connection to server" )
+          raise LdapError, "No such address or other socket error."
+        rescue Errno::ECONNREFUSED
+          raise LdapError, "Server #{server[:host]} refused connection on port #{server[:port]}."
         end
 
         if server[:encryption]

spec/spec_helper.rb

@@ -1,3 +1,5 @@
+require 'net/ldap'
+
 Spec::Runner.configure do |config|
   config.mock_with :flexmock
 end

spec/unit/ldap_spec.rb

@@ -0,0 +1,48 @@
+require 'spec_helper'
+
+describe Net::LDAP::Connection do
+  describe "initialize" do
+    context "when host is not responding" do
+      before(:each) do
+        flexmock(TCPSocket).
+          should_receive(:new).and_raise(Errno::ECONNREFUSED)
+      end
+      
+      it "should raise LdapError" do
+        lambda {
+          Net::LDAP::Connection.new(
+            :server => 'test.mocked.com', 
+            :port   => 636)
+        }.should raise_error(Net::LDAP::LdapError)
+      end
+    end
+    context "when host is blocking the port" do
+      before(:each) do
+        flexmock(TCPSocket).
+          should_receive(:new).and_raise(SocketError)
+      end
+      
+      it "should raise LdapError" do
+        lambda {
+          Net::LDAP::Connection.new(
+            :server => 'test.mocked.com', 
+            :port   => 636)
+        }.should raise_error(Net::LDAP::LdapError)
+      end
+    end
+    context "on other exceptions" do
+      before(:each) do
+        flexmock(TCPSocket).
+          should_receive(:new).and_raise(NameError)
+      end
+      
+      it "should rethrow the exception" do
+        lambda {
+          Net::LDAP::Connection.new(
+            :server => 'test.mocked.com', 
+            :port   => 636)
+        }.should raise_error(NameError)
+      end
+    end
+  end
+end