Add amend commit feature

lib/dialogs/commit-dialog.coffee

@@ -17,13 +17,22 @@ class CommitDialog extends Dialog
         @button click: 'cancel', =>
           @i class: 'icon x'
           @span 'Cancel'
+        @input type: 'checkbox', id: 'amend', outlet: 'amendCheckbox'
+        @label 'Amend', for: 'amend'
+
 
   activate: ->
     super()
     @msg.val('')
     @msg.focus()
     return
 
+  amend: ->
+    return @amendCheckbox.prop('checked')
+
+  resetAmend: ->
+    @amendCheckbox.prop('checked', false)
+
   colorLength: ->
     too_long = false
     for line, i in @msg.val().split("\n")

lib/git-control-view.coffee

@@ -165,13 +165,15 @@ class GitControlView extends View
     return unless @filesView.hasSelected()
 
     msg = @commitDialog.getMessage()
+    amend = @commitDialog.amend()
+    @commitDialog.resetAmend()
 
     files = @filesView.getSelected()
     @filesView.unselectAll()
 
     git.add(files.add)
       .then -> git.remove(files.rem)
-      .then -> git.commit(msg)
+      .then -> git.commit(msg, amend)
       .then => @update()
     return
 

lib/git.coffee

@@ -149,11 +149,12 @@ module.exports =
       atomRefresh()
       return parseDefault(data)
 
-  commit: (message) ->
+  commit: (message, amend) ->
     message = message or Date.now()
     message = message.replace(/"/g, '\\"')
+    amendOpt = if amend then "--amend " else "--allow-empty-message"
 
-    return callGit "commit --allow-empty-message -m \"#{message}\"", (data) ->
+    return callGit "commit #{amendOpt} -m \"#{message}\"", (data) ->
       atomRefresh()
       return parseDefault(data)