Bug 1666247 - Part 3: Disable tab modal print on about:sessionrestore r=emalysz

Differential Revision: https://phabricator.services.mozilla.com/D116877

toolkit/components/printing/content/printUtils.js

@@ -255,6 +255,15 @@ var PrintUtils = {
       !PRINT_ALWAYS_SILENT &&
       (!openWindowInfo || openWindowInfo.isForWindowDotPrint)
     ) {
+      if (
+        aBrowsingContext.currentWindowGlobal.documentURI.spec ==
+        "about:sessionrestore"
+      ) {
+        // Tab modal print on about:sessionrestore causes a crash, disable it
+        // for now  (bug 1714639).
+        return null;
+      }
+
       let browsingContext = aBrowsingContext;
       let focusedBc = Services.focus.focusedContentBrowsingContext;
       if (