Fix bug when positioning cursors after the fold-marker

package.json

@@ -54,7 +54,7 @@
     "service-hub": "^0.7.0",
     "source-map-support": "^0.3.2",
     "temp": "0.8.1",
-    "text-buffer": "9.0.0-beta5",
+    "text-buffer": "9.0.0-beta6",
     "typescript-simple": "1.0.0",
     "underscore-plus": "^1.6.6",
     "yargs": "^3.23.0"

spec/text-editor-component-spec.js

@@ -1249,6 +1249,17 @@ describe('TextEditorComponent', function () {
       expect(cursorRect.width).toBeCloseTo(rangeRect.width, 0)
     })
 
+    it('positions cursors after the fold-marker when a fold ends the line', async function () {
+      editor.foldBufferRow(0)
+      await nextViewUpdatePromise()
+      editor.setCursorScreenPosition([0, 30])
+      await nextViewUpdatePromise()
+
+      let cursorRect = componentNode.querySelector('.cursor').getBoundingClientRect()
+      let foldMarkerRect = componentNode.querySelector('.fold-marker').getBoundingClientRect()
+      expect(cursorRect.left).toBeCloseTo(foldMarkerRect.right, 0)
+    })
+
     it('positions cursors correctly after character widths are changed via a stylesheet change', async function () {
       atom.config.set('editor.fontFamily', 'sans-serif')
       editor.setCursorScreenPosition([0, 16])

src/lines-tile-component.coffee

@@ -4,6 +4,7 @@ HighlightsComponent = require './highlights-component'
 AcceptFilter = {acceptNode: -> NodeFilter.FILTER_ACCEPT}
 TokenTextEscapeRegex = /[&"'<>]/g
 MaxTokenLength = 20000
+ZERO_WIDTH_NBSP = '\ufeff'
 
 cloneObject = (object) ->
   clone = {}
@@ -225,6 +226,15 @@ class LinesTileComponent
       lineNode.appendChild(textNode)
       textNodes.push(textNode)
 
+    if lineText.endsWith(@presenter.displayLayer.foldCharacter)
+      # Insert a zero-width non-breaking whitespace, so that
+      # LinesYardstick can take the fold-marker::after pseudo-element
+      # into account during measurements when such marker is the last
+      # character on the line.
+      textNode = @domElementPool.buildText(ZERO_WIDTH_NBSP)
+      lineNode.appendChild(textNode)
+      textNodes.push(textNode)
+
     @textNodesByLineId[id] = textNodes
     lineNode