Fix handling compositions in Firefox on Linux

Fixes #489

src/trix/controllers/input_controller.coffee

@@ -161,6 +161,9 @@ class Trix.InputController extends Trix.BasicObject
         @responder?.insertString(string)
         @setInputSummary(textAdded: string, didDelete: @selectionIsExpanded())
 
+    keyup: (event) ->
+      @inputSummary.didInput = true
+
     textInput: (event) ->
       # Handle autocapitalization
       {data} = event

test/src/system/composition_input_test.coffee

@@ -164,6 +164,26 @@ testGroup "Composition input", template: "editor_empty", ->
             assert.locationRange(index: 0, offset: 2)
             expectDocument("éé\n")
 
+  # Simulates compositions in Firefox on Linux, which aren't preceded by
+  # keydown and don't dispatch input after compositionupdate.
+  test "composition with limited contextual keyboard and input events", (expectDocument) ->
+    element = getEditorElement()
+    element.editor.insertString("i")
+    element.editor.setSelectedRange(1)
+    defer ->
+      triggerEvent(element, "keyup", charCode: 0, keyCode: 0, which: 0)
+      triggerEvent(element, "compositionstart", data: "")
+      triggerEvent(element, "compositionupdate", data: "ó")
+      node = document.createTextNode("ó")
+      insertNode(node)
+      selectNode(node)
+      defer ->
+        triggerEvent(element, "compositionend", data: "ó")
+        triggerEvent(element, "input")
+        typeCharacters "n", ->
+          assert.locationRange(index: 0, offset: 3)
+          expectDocument("ión\n")
+
 removeCharacters = (direction, callback) ->
   selection = rangy.getSelection()
   range = selection.getRangeAt(0)