Run git submodule update after initial clone

Some repositories require that submodules be initialized and updated to
be properly built.  This is now done during the download phase for every
repository.

lib/cocoapods/downloader/git.rb

@@ -76,6 +76,7 @@ def update_cache
           git "reset --hard HEAD"
           git "clean -d -x -f"
           git "pull"
+          git "submodule update"
         end
       end
 
@@ -111,6 +112,7 @@ def download_tag
           git "fetch origin tags/#{options[:tag]}"
           git "reset --hard FETCH_HEAD"
           git "checkout -b activated-pod-commit"
+          git "submodule update --init"
         end
       end
 
@@ -135,6 +137,9 @@ def download_branch
 
       def clone(from, to)
         git "clone \"#{from}\" \"#{to}\""
+        Dir.chdir(to) do
+          git "submodule update --init"
+        end
       end
     end
 

spec/functional/downloader_spec.rb

@@ -39,6 +39,28 @@ module Pod
         (@pod.root + 'README').read.strip.should == 'v1.0'
       end
 
+      it "initializes submodules when checking out a specific commit" do
+        @pod.top_specification.stubs(:source).returns(
+          :git => fixture('banana-lib'), :commit => '6cc9afc'
+        )
+        downloader = Downloader.for_pod(@pod)
+        downloader.download
+
+        (@pod.root + 'README').read.strip.should == 'post v1.0'
+        (@pod.root + 'libPusher/README.md').read.strip.should.match /^libPusher/
+      end
+
+      it "initializes submodules when checking out a specific tag" do
+        @pod.top_specification.stubs(:source).returns(
+          :git => fixture('banana-lib'), :tag => 'v1.1'
+        )
+        downloader = Downloader.for_pod(@pod)
+        downloader.download
+
+        (@pod.root + 'README').read.strip.should == 'post v1.0'
+        (@pod.root + 'libPusher/README.md').read.strip.should.match /^libPusher/
+      end
+
       it "prepares the cache if it does not exits" do
         @pod.top_specification.stubs(:source).returns(
           :git => fixture('banana-lib'), :commit => 'fd56054'