From ec3a1a80cd0df41f01c52b4afcc009e061fece34 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 30 Jan 2013 12:48:29 -0700
Subject: [PATCH] Restore invalidated anchor points on undo/redo of a change

---
 spec/app/buffer-spec.coffee | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/spec/app/buffer-spec.coffee b/spec/app/buffer-spec.coffee
index 84fea60db..f6ae76471 100644
--- a/spec/app/buffer-spec.coffee
+++ b/spec/app/buffer-spec.coffee
@@ -665,7 +665,7 @@ describe 'Buffer', ->
       anchor2Id = buffer.addAnchorPoint([4, 23], ignoreSameLocationInserts: true)
       anchor3Id = buffer.addAnchorPoint([4, 23], surviveSurroundingChanges: true)
 
-    describe "when the buffer changes", ->
+    describe "when the buffer changes due to a new operation", ->
       describe "when the change precedes the anchor point", ->
         it "moves the anchor", ->
           buffer.insert([4, 5], '...')
@@ -716,6 +716,21 @@ describe 'Buffer', ->
             buffer.undo()
             expect(buffer.getAnchorPoint(anchor1Id)).toEqual [4, 23]
 
+    describe "when the buffer changes due to the undo or redo of a previous operation", ->
+      it "restores invalidated anchor points when undoing/redoing in the other direction", ->
+        buffer.change([[4, 21], [4, 24]], "foo")
+        expect(buffer.getAnchorPoint(anchor1Id)).toBeUndefined()
+        anchor4Id = buffer.addAnchorPoint([4, 23])
+        buffer.undo()
+        expect(buffer.getAnchorPoint(anchor1Id)).toEqual [4, 23]
+        expect(buffer.getAnchorPoint(anchor4Id)).toBeUndefined()
+        anchor5Id = buffer.addAnchorPoint([4, 23])
+        buffer.redo()
+        expect(buffer.getAnchorPoint(anchor4Id)).toEqual [4, 23]
+        expect(buffer.getAnchorPoint(anchor5Id)).toBeUndefined()
+        buffer.undo()
+        expect(buffer.getAnchorPoint(anchor5Id)).toEqual [4, 23]
+
   describe "anchors", ->
     [anchor, destroyHandler] = []