Fix delete undo (#2240)

* Fix undo after a selection snapshot

* Add a test to cover the text deletion case

* Fix lint

* Use the new whitoutMerging flag instead

* cleanup + fix function call

packages/slate/src/changes/on-selection.js

@@ -606,7 +606,9 @@ Changes.setStart = (change, ...args) => {
 }
 
 Changes.snapshotSelection = change => {
-  change.select(change.value.selection, { snapshot: true })
+  change.withoutMerging(c =>
+    c.select(change.value.selection, { snapshot: true })
+  )
 }
 
 /**

packages/slate/src/models/change.js

@@ -47,11 +47,10 @@ class Change {
    * history if needed.
    *
    * @param {Operation|Object} operation
-   * @param {Object} options
    * @return {Change}
    */
 
-  applyOperation(operation, options = {}) {
+  applyOperation(operation) {
     const { operations } = this
     let { value } = this
     let { history } = value

packages/slate/test/history/undo/remove-text.js

@@ -0,0 +1,33 @@
+/** @jsx h */
+
+import h from '../../helpers/h'
+
+export default function(value) {
+  return value
+    .change()
+    .moveAnchorForward(4)
+    .moveFocusForward(7)
+    .delete()
+    .value.change()
+    .undo().value
+}
+
+export const input = (
+  <value>
+    <document>
+      <paragraph>
+        <cursor />one two
+      </paragraph>
+    </document>
+  </value>
+)
+
+export const output = (
+  <value>
+    <document>
+      <paragraph>
+        one <anchor />two<focus />
+      </paragraph>
+    </document>
+  </value>
+)