Fix bug where deletions' end position wasn't mapped forward

src/changeset.js

@@ -56,9 +56,9 @@ export class ChangeSet {
     if (maps.length == 0) return this
 
     maps = this.maps.concat(maps)
-    let inserted = [], deleted = this.deleted.concat()
+    let inserted = [], deleted = []
 
-    // Map existing inserted spans forward
+    // Map existing inserted and deleted spans forward
     for (let i = 0; i < this.inserted.length; i++) {
       let span = this.inserted[i], {from, to} = span
       for (let j = this.maps.length; j < maps.length && to > from; j++) {
@@ -67,6 +67,11 @@ export class ChangeSet {
       }
       if (to > from) inserted.push(from != span.from || to != span.to ? new Span(from, to, span.data) : span)
     }
+    for (let i = 0; i < this.deleted.length; i++) {
+      let span = this.deleted[i], pos = span.pos
+      for (let j = this.maps.length; j < maps.length; j++) pos = maps[j].map(pos, -1)
+      deleted.push(pos == span.pos ? span : new DeletedSpan(span.from, span.to, span.data, pos, span.slice))
+    }
 
     // Add spans for new steps.
     let newBoundaries = [] // Used to make sure new insertions are checked for merging

test/test-changes.js

@@ -63,6 +63,11 @@ describe("ChangeSet", () => {
     (tr, p) => tr.insert(p("a"), schema.text("--")),
     (tr, p) => tr.delete(p("a"), p("a") + 1)
   ], {a: 1}))
+
+  it("maps deletions forward", find(doc(p("f<a>ooba<b>r<c>")), [
+    (tr, p) => tr.delete(p("b"), p("c")),
+    (tr, p) => tr.insert(p("a"), schema.text("OKAY"))
+  ], {a: 4}, {b: "r"}))
 })
 
 function find(doc, build, insertions, deletions, sep) {