Duplicate multiple selections and multiple lines; folds are broken

spec/editor-spec.coffee

@@ -2669,6 +2669,30 @@ describe "Editor", ->
           expect(editor.lineForBufferRow(9)).toBe '  }; return sort(Array.apply(this, arguments)); };'
           expect(editor.getSelectedBufferRange()).toEqual [[9, 3], [9, 49]]
 
+  describe ".duplicateLines()", ->
+    it "for each selection, duplicates all buffer lines intersected by the selection", ->
+      editor.foldBufferRow(4)
+      editor.setCursorBufferPosition([2, 5])
+      editor.addSelectionForBufferRange([[3, 0], [8, 0]])
+
+      editor.duplicateLine()
+
+      expect(editor.getTextInBufferRange([[2, 0], [13, 5]])).toBe  """
+        \    if (items.length <= 1) return items;
+            if (items.length <= 1) return items;
+            var pivot = items.shift(), current, left = [], right = [];
+            while(items.length > 0) {
+              current = items.shift();
+              current < pivot ? left.push(current) : right.push(current);
+            }
+            var pivot = items.shift(), current, left = [], right = [];
+            while(items.length > 0) {
+              current = items.shift();
+              current < pivot ? left.push(current) : right.push(current);
+            }
+      """
+      expect(editor.getSelectedBufferRanges()).toEqual [[[3, 5], [3, 5]], [[9, 0], [14, 0]]]
+
   describe ".shouldPromptToSave()", ->
     it "returns false when an edit session's buffer is in use by more than one session", ->
       jasmine.unspy(editor, 'shouldPromptToSave')

src/editor.coffee

@@ -949,27 +949,16 @@ class Editor extends Model
 
   # Duplicate the most recent cursor's current line.
   duplicateLine: ->
-    return unless @getSelection().isEmpty()
-
     @transact =>
-      cursorPosition = @getCursorBufferPosition()
-      cursorRowFolded = @isFoldedAtCursorRow()
-      if cursorRowFolded
-        screenRow = @screenPositionForBufferPosition(cursorPosition).row
-        bufferRange = @bufferRangeForScreenRange([[screenRow], [screenRow + 1]])
-      else
-        bufferRange = new Range([cursorPosition.row], [cursorPosition.row + 1])
+      for selection in @getSelectionsOrderedByBufferPosition().reverse()
+        selectedBufferRange = selection.getBufferRange()
+        [startRow, endRow] = selection.getBufferRowRange()
+        endRow++
+        rangeToDuplicate = [[startRow, 0], [endRow, 0]]
+        textToDuplicate = @getTextInBufferRange(rangeToDuplicate)
+        @buffer.insert([endRow, 0], textToDuplicate)
 
-      insertPosition = new Point(bufferRange.end.row)
-      if insertPosition.row > @buffer.getLastRow()
-        @unfoldCurrentRow() if cursorRowFolded
-        @buffer.append("\n#{@getTextInBufferRange(bufferRange)}")
-        @foldCurrentRow() if cursorRowFolded
-      else
-        @buffer.insert(insertPosition, @getTextInBufferRange(bufferRange))
-
-      @setCursorScreenPosition(@getCursorScreenPosition().translate([1]))
-      @foldCurrentRow() if cursorRowFolded
+        selection.setBufferRange(selectedBufferRange.translate([endRow - startRow, 0]))
 
   mutateSelectedText: (fn) ->
     @transact => fn(selection) for selection in @getSelections()