Uncaught type error

Today, while editing an SVG file, I invoked the Emmet "wrap" command (ctrl-w) and started to type a "g" take to wrap my svg paths in a group.

The svg file was displaying color tokens, even though i really didnt need them.

I got this:


Stack trace:

```
TypeError: Cannot read property 'tokenAtBufferColumn' of undefined
at TokenizedBuffer.module.exports.TokenizedBuffer.tokenForPosition (/Applications/Atom.app/Contents/Resources/app/src/tokenized-buffer.js:503:38)
at TokenizedBuffer.module.exports.TokenizedBuffer.scopeDescriptorForPosition (/Applications/Atom.app/Contents/Resources/app/src/tokenized-buffer.js:496:22)
at DisplayBuffer.module.exports.DisplayBuffer.scopeDescriptorForBufferPosition (/Applications/Atom.app/Contents/Resources/app/src/display-buffer.js:1044:35)
at color-marker.module.exports.MarkerMixin.getScope (/Users/stevelombardi/.atom/packages/atom-color-highlight/lib/marker-mixin.coffee:59:42)
at color-marker.module.exports.MarkerMixin.hiddenDueToComment (/Users/stevelombardi/.atom/packages/atom-color-highlight/lib/marker-mixin.coffee:67:14)
at color-marker.module.exports.MarkerMixin.isHidden (/Users/stevelombardi/.atom/packages/atom-color-highlight/lib/marker-mixin.coffee:53:6)
at color-marker.module.exports.MarkerMixin.show (/Users/stevelombardi/.atom/packages/atom-color-highlight/lib/marker-mixin.coffee:18:33)
at color-marker.module.exports.MarkerMixin.updateVisibility (/Users/stevelombardi/.atom/packages/atom-color-highlight/lib/marker-mixin.coffee:43:27)
at color-marker.module.exports.MarkerMixin.onMarkerChanged (/Users/stevelombardi/.atom/packages/atom-color-highlight/lib/marker-mixin.coffee:40:6)
at /Users/stevelombardi/.atom/packages/atom-color-highlight/lib/marker-mixin.coffee:32:52
at Emitter.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:82:11)
at Marker.module.exports.Marker.resumeChangeEvents (/Applications/Atom.app/Contents/Resources/app/src/marker.js:319:38)
at DisplayBuffer.module.exports.DisplayBuffer.resumeMarkerChangeEvents (/Applications/Atom.app/Contents/Resources/app/src/display-buffer.js:1390:16)
at DisplayBuffer.module.exports.DisplayBuffer.emitDidChange (/Applications/Atom.app/Contents/Resources/app/src/display-buffer.js:321:19)
at DisplayBuffer.module.exports.DisplayBuffer.handleBufferMarkersUpdated (/Applications/Atom.app/Contents/Resources/app/src/display-buffer.js:1588:21)
at /Applications/Atom.app/Contents/Resources/app/src/display-buffer.js:5:61
at Emitter.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/node_modules/event-kit/lib/emitter.js:82:11)
at TextBuffer.module.exports.TextBuffer.applyPatch (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:595:20)
at BufferPatch.module.exports.BufferPatch.applyTo (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/buffer-patch.js:74:21)
at Transaction.module.exports.Transaction.applyTo (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/transaction.js:60:29)
at History.module.exports.History.undo (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/history.js:87:24)
at TextBuffer.module.exports.TextBuffer.undo (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:675:27)
at TextEditor.module.exports.TextEditor.undo (/Applications/Atom.app/Contents/Resources/app/src/text-editor.js:1141:26)
at PromptView.module.exports.PromptView.undo (/Users/stevelombardi/.atom/packages/emmet/lib/prompt.coffee:38:11)
at PromptView.module.exports.PromptView.handleUpdate (/Users/stevelombardi/.atom/packages/emmet/lib/prompt.coffee:41:4)
at /Users/stevelombardi/.atom/packages/emmet/lib/prompt.coffee:22:5
at TextEditor.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/emissary/lib/emitter.js:118:15)
at /Applications/Atom.app/Contents/Resources/app/src/text-editor.js:171:24
at Emitter.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/node_modules/event-kit/lib/emitter.js:82:11)
at /Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:1142:25
```

錯誤源自 atom-color-highlight 套件的 marker-mixin.coffee 檔案第 59 行，其中 getScope 在未定義的物件上呼叫了 tokenForPosition。先檢查 marker-mixin.coffee 檔案，以了解 MarkerMixin 類別及其與 Atom 標記化緩衝區的互動。編輯 SVG 檔案並使用 Emmet wrap 指令來重現問題。檢查錯誤發生時緩衝區位置是否有效。

由索引模型根據 Issue 內容生成。