Don't create folds for empty ranges

spec/selection-spec.coffee

@@ -101,3 +101,22 @@ describe "Selection", ->
       selection.setBufferRange [[2, 0], [3, 0]]
       selection.insertText("\r\n", autoIndent: true)
       expect(buffer.lineForRow(2)).toBe "  "
+
+  describe ".fold()", ->
+    it "folds the buffer range spanned by the selection", ->
+      selection.setBufferRange([[0, 3], [1, 6]])
+      selection.fold()
+
+      expect(selection.getScreenRange()).toEqual([[0, 4], [0, 4]])
+      expect(selection.getBufferRange()).toEqual([[1, 6], [1, 6]])
+      expect(editor.lineTextForScreenRow(0)).toBe "var#{editor.displayLayer.foldCharacter}sort = function(items) {"
+      expect(editor.isFoldedAtBufferRow(0)).toBe(true)
+
+    it "doesn't create a fold when the selection is empty", ->
+      selection.setBufferRange([[0, 3], [0, 3]])
+      selection.fold()
+
+      expect(selection.getScreenRange()).toEqual([[0, 3], [0, 3]])
+      expect(selection.getBufferRange()).toEqual([[0, 3], [0, 3]])
+      expect(editor.lineTextForScreenRow(0)).toBe "var quicksort = function () {"
+      expect(editor.isFoldedAtBufferRow(0)).toBe(false)

src/selection.coffee

@@ -628,8 +628,9 @@ class Selection extends Model
   # Public: Creates a fold containing the current selection.
   fold: ->
     range = @getBufferRange()
-    @editor.foldBufferRange(range)
-    @cursor.setBufferPosition(range.end)
+    unless range.isEmpty()
+      @editor.foldBufferRange(range)
+      @cursor.setBufferPosition(range.end)
 
   # Private: Increase the indentation level of the given text by given number
   # of levels. Leaves the first line unchanged.