Fix up hub submodule

README.md

@@ -179,6 +179,17 @@ login" below for details.
     $ git compare myfork patch
     > open http://github.com/myfork/compare/patch
 
+### git submodule
+    $ hub submodule add wycats/bundler vendor/bundler
+    > git submodule add git://github.com/wycats/bundler.git vendor/bundler
+
+    $ hub submodule add -p wycats/bundler vendor/bundler
+    > git submodule add git@github.com:wycats/bundler.git vendor/bundler
+
+    $ hub submodule add -b ryppl ryppl/pip vendor/bundler
+    > git submodule add -b ryppl git://github.com/ryppl/pip.git vendor/pip
+
+
 ### git help
 
     $ git help

lib/hub/commands.rb

@@ -95,10 +95,24 @@ def clone(args)
     #
     # $ hub submodule add -p wycats/bundler vendor/bundler
     # > git submodule add git@github.com:wycats/bundler.git vendor/bundler
+    #
+    # $ hub submodule add -b ryppl ryppl/pip vendor/bundler
+    # > git submodule add -b ryppl git://github.com/ryppl/pip.git vendor/pip
     def submodule(args)
       return unless index = args.index('add')
       args.delete_at index
+
+      branch = args.index('-b') || args.index('--branch')
+      if branch 
+        args.delete_at branch
+        branch_name = args.delete_at branch
+      end
+
       clone(args)
+
+      if branch_name
+        args.insert branch, '-b', branch_name
+      end
       args.insert index, 'add'
     end
 

test/hub_test.rb

@@ -108,17 +108,26 @@ def test_private_remote_origin_as_normal
 
   def test_public_submodule
     input   = "submodule add wycats/bundler vendor/bundler"
-    command = "git submodule add git://github.com/wycats.bundler.git"
+    command = "git submodule add git://github.com/wycats/bundler.git vendor/bundler"
+    assert_command input, command
   end
 
   def test_private_submodule
     input   = "submodule add -p grit vendor/grit"
-    command = "git submodule add git@github.com:tpw/grit.git"
+    command = "git submodule add git@github.com:tpw/grit.git vendor/grit"
+    assert_command input, command
+  end
+
+  def test_submodule_branch
+    input   = "submodule add -b ryppl ryppl/pip vendor/pip"
+    command = "git submodule add -b ryppl git://github.com/ryppl/pip.git vendor/pip"
+    assert_command input, command
   end
 
   def test_submodule_with_args
     input   = "submodule -q add --bare -- grit grit"
     command = "git submodule -q add --bare -- git://github.com/tpw/grit.git grit"
+    assert_command input, command
   end
 
   def test_private_remote