Additional check to ensure pdfViewer object is defined before handleMouseWheel event accesses its property isInPresentationMode

9 years ago · 7fec8de502
1 changed files with 1 additions and 1 deletions
--- a/web/app.js
+++ b/web/app.js
@ -2000,7 +2000,7 @@ function webViewerPageChanging(e) {
 var zoomDisabled = false, zoomDisabledTimeout;
 function handleMouseWheel(evt) {
  var pdfViewer = PDFViewerApplication.pdfViewer;
-  if (pdfViewer.isInPresentationMode) {
+  if (!pdfViewer || pdfViewer.isInPresentationMode) {
    return;
  }