Uncaught TypeError: Cannot read property 'NaN' of undefined.

Tried to edit a stylsheet and got `Uncaught TypeError: Cannot read property 'NaN' of undefined`. Seems to be ever since I upgraded my OS to High Seirra version 10.13. Pigments now causes the stylesheets to be unresponsive.

**Atom**: 1.20.1 x64
**Electron**: 1.6.9
**OS**: Mac OS X 10.13
**Thrown From**: [pigments](https://github.com/abe33/atom-pigments) package 0.40.2

### Stack Trace

Uncaught TypeError: Cannot read property 'NaN' of undefined

```
At /Applications/Atom.app/Contents/Resources/app/src/text-editor-component.js:958

TypeError: Cannot read property 'NaN' of undefined
at TextEditorComponent.renderedScreenLineForRow (/Applications/Atom.app/Contents/Resources/app/src/text-editor-component.js:958:37)
at TextEditorComponent.pixelLeftForRowAndColumn (/Applications/Atom.app/Contents/Resources/app/src/text-editor-component.js:2364:35)
at TextEditorComponent.pixelPositionForScreenPosition (/Applications/Atom.app/Contents/Resources/app/src/text-editor-component.js:204:46)
at HTMLElement.pixelPositionForScreenPosition (/Applications/Atom.app/Contents/Resources/app/src/text-editor-element.js:243:32)
at /packages/pigments/lib/color-buffer-element.coffee:327:36)
at HTMLElement.ColorBufferElement.updateDotDecorationsOffsets (/packages/pigments/lib/color-buffer-element.coffee:319:7)
at /packages/pigments/lib/color-buffer-element.coffee:250:14
at Array.forEach (native)
at /packages/pigments/lib/color-buffer-element.coffee:249:20
at Function.module.exports.Emitter.simpleDispatch (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:25:20)
at Emitter.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:141:34)
at /Applications/Atom.app/Contents/Resources/app/src/text-editor.js:626:38
at Function.module.exports.Emitter.simpleDispatch (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:25:20)
at Emitter.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:141:34)
at DisplayLayer.emitDidChangeSyncEvent (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/display-layer.js:823:24)
at /Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:757:35
at Map.forEach (native)
at TextBuffer.module.exports.TextBuffer.emitDidChangeEvent (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:756:47)
at TextBuffer.module.exports.TextBuffer.applyChange (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:739:18)
at TextBuffer.module.exports.TextBuffer.revertToCheckpoint (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:946:22)
at TextBuffer.module.exports.TextBuffer.transact (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:897:20)
at TextEditor.module.exports.TextEditor.transact (/Applications/Atom.app/Contents/Resources/app/src/text-editor.js:1673:32)
at /Applications/Atom.app/Contents/Resources/app/src/text-editor.js:1234:30
at TextEditor.module.exports.TextEditor.mergeSelections (/Applications/Atom.app/Contents/Resources/app/src/text-editor.js:2617:49)
at TextEditor.module.exports.TextEditor.mergeIntersectingSelections (/Applications/Atom.app/Contents/Resources/app/src/text-editor.js:2583:41)
at TextEditor.module.exports.TextEditor.mutateSelectedText (/Applications/Atom.app/Contents/Resources/app/src/text-editor.js:1232:25)
at TextEditor.module.exports.TextEditor.insertText (/Applications/Atom.app/Contents/Resources/app/src/text-editor.js:1198:25)
at TextEditor.object.(anonymous function) [as insertText] (/Applications/Atom.app/Contents/Resources/app/node_modules/underscore-plus/lib/underscore-plus.js:77:33)
at TextEditorComponent.didTextInput (/Applications/Atom.app/Contents/Resources/app/src/text-editor-component.js:1651:28)
```

### Commands

```
```

### Non-Core Packages

```
atom-beautify 0.30.5
atom-bootstrap4 1.4.0
atom-css-comb 3.3.1
atom-material-syntax-dark 1.0.0
atom-material-ui 2.0.4
autoprefixer 3.7.1
busy 0.7.0
emmet 2.4.3
file-icons 2.1.12
language-gitignore 0.3.0
minimap 4.29.7
php-cs-fixer 4.1.1
pigments 0.40.2
tree-view-git-status 1.4.0
w3c-validation 0.4.0
```

The error originates in /packages/pigments/lib/color-buffer-element.coffee around line 327, where pixelPositionForScreenPosition is called. Start by examining the updateDotDecorationsOffsets method and the surrounding code to understand how screen positions are calculated. Check for any assumptions about row/column values that might lead to NaN. Reproduce by editing a stylesheet in Atom with the pigments package enabled and inspect the state when the error occurs.

Escrita pelo modelo de indexação a partir do texto da issue.