Merge pull request #205 from nex3/v1.3

Don't load an adapter if it can't be required.

lib/listen/adapter.rb

@@ -206,6 +206,8 @@ def self.load_dependent_adapter
       return true if @loaded
       require adapter_gem
       return @loaded = true
+    rescue LoadError
+      false
     end
 
     # Runs a tests to determine if the adapter can actually pick up

spec/listen/adapter_spec.rb

@@ -87,12 +87,23 @@
   end
 
   describe '.load_dependend_adapter' do
+    after(:each) { described_class.instance_variable_set('@loaded', nil) }
+
     it 'returns true (success) even if the adapter_gem has already been required' do
       described_class.stub(:adapter_gem => 'already_loaded_gem')
       described_class.stub(:require => false)
 
       described_class.load_dependent_adapter.should be_true
     end
+
+    it 'returns false (failure) if the adapter_gem cannot be required' do
+      described_class.stub(:adapter_gem => 'unloadable_gem')
+      described_class.stub(:require) do
+        raise LoadError.new('no such file to load -- unloadable_gem')
+      end
+
+      described_class.load_dependent_adapter.should be_false
+    end
   end
 
   Listen::Adapter::OPTIMIZED_ADAPTERS.each do |adapter|