In pdf viewer, an error occurs when zooming

Hello!

In pdf viewer, an error occurs when zooming.

Configuration:

• Web browser: Chrome, Firefox, IE, Edge
• Operating system: Win 10
• PDF.js version: 1.7.343

Steps to reproduce:

1. open the document
2. zoom in/out
3. wait a couple of minutes
4. zoom in/out

Error in console:

Uncaught TypeError: Cannot read property 'rotation' of undefined
    at PDFPageView_transform [as cssTransform] (VM9875 pdf.viewer.js:16517)
    at PDFPageView_update [as update] (VM9875 pdf.viewer.js:16481)
    at PDFViewer.pdfViewer_setScaleUpdatePages [as _setScaleUpdatePages] (VM14856 pdf.viewer.js:18718)
    at PDFViewer_setScale [as _setScale] (VM14856 pdf.viewer.js:18743)
    at PDFViewer.set currentScaleValue [as currentScaleValue] (VM14856 pdf.viewer.js:18517)
    at Object.pdfViewZoomIn [as zoomIn] (VM9875 pdf.viewer.js:12173)
    at webViewerWheel (VM9875 pdf.viewer.js:13277)

This happens in the cssTransform function https://github.com/mozilla/pdf.js/blob/master/web/pdf_page_view.js#L281-L282

this.paintedViewportMap.get (target) is ‘undefined’, since this.paintedViewportMap.delete(this.canvas) is called after a few minutes.

The error appeared after the pull request https://github.com/mozilla/pdf.js/pull/7977/files

[Akaban]

Hello !

Same here, if I zoom in I don’t have the error but while zooming out I get it.

React 16 here

If someone knows something would be greatly appreciated !

[ilnur-slv]

@Snuffleupagus Works well!