Add hotkey for "reply with selected text" to Issueable

app/assets/javascripts/shortcuts_issueable.coffee

@@ -11,9 +11,35 @@ class @ShortcutsIssueable extends ShortcutsNavigation
       $('.js-milestone').select2('open')
       return false
     )
-    
+    Mousetrap.bind('r', =>
+      @replyWithSelectedText()
+      return false
+    )
+
     if isMergeRequest
       @enabledHelp.push('.hidden-shortcut.merge_requests')
     else
       @enabledHelp.push('.hidden-shortcut.issues')
 
+  replyWithSelectedText: ->
+    if window.getSelection
+      selected = window.getSelection().toString()
+      replyField = $('.js-main-target-form #note_note')
+
+      return if selected.trim() == ""
+
+      # Put a '>' character before each non-empty line in the selection
+      quote = _.map selected.split("\n"), (val) ->
+        "> #{val}\n" if val.trim() != ''
+
+      # If replyField already has some content, add a newline before our quote
+      separator = replyField.val().trim() != "" and "\n" or ''
+
+      replyField.val (_, current) ->
+        current + separator + quote.join('') + "\n"
+
+      # Trigger autosave for the added text
+      replyField.trigger('input')
+
+      # Focus the input field
+      replyField.focus()