Merge pull request #16455 from fordhurley/fix-unique-editor-ids

Ensure that new editors get unique ids

spec/text-editor-spec.js

@@ -20,6 +20,17 @@ describe('TextEditor', () => {
     await atom.packages.activatePackage('language-javascript')
   })
 
+  it('generates unique ids for each editor', async () => {
+    // Deserialized editors are initialized with the serialized id. We can
+    // initialize an editor with what we expect to be the next id:
+    const deserialized = new TextEditor({id: editor.id+1})
+    expect(deserialized.id).toEqual(editor.id+1)
+
+    // The id generator should skip the id used up by the deserialized one:
+    const fresh = new TextEditor()
+    expect(fresh.id).toNotEqual(deserialized.id)
+  })
+
   describe('when the editor is deserialized', () => {
     it('restores selections and folds based on markers in the buffer', async () => {
       editor.setSelectedBufferRange([[1, 2], [3, 4]])

src/text-editor.js

@@ -119,6 +119,10 @@ class TextEditor {
     }
 
     this.id = params.id != null ? params.id : nextId++
+    if (this.id >= nextId) {
+      // Ensure that new editors get unique ids:
+      nextId = this.id + 1
+    }
     this.initialScrollTopRow = params.initialScrollTopRow
     this.initialScrollLeftColumn = params.initialScrollLeftColumn
     this.decorationManager = params.decorationManager