Merge pull request #8499 from Snuffleupagus/issue-8498

Prevent console errors when clicking to change page while in Presentation Mode (issue 8498)

web/pdf_presentation_mode.js

@@ -288,7 +288,12 @@ class PDFPresentationMode {
       if (!isInternalLink) {
         // Unless an internal link was clicked, advance one page.
         evt.preventDefault();
-        this.pdfViewer.currentPageNumber += (evt.shiftKey ? -1 : 1);
+
+        if (evt.shiftKey) {
+          this._goToPreviousPage();
+        } else {
+          this._goToNextPage();
+        }
       }
     }
   }