From 9de30c4ff01a3bbd40d74a86a64d90ffc1719ed0 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sat, 4 Dec 2021 16:40:48 +0100
Subject: [PATCH] Ensure that the viewer handles `BaseViewer` initialization
 failures

*This patch can be tested e.g. with the `poppler-85140-0.pdf` document from the test-suite.*

For some sufficiently corrupt documents the `getDocument` call will succeed, but fetching even the very first page fails. Currently we only print error messages (in the console) from the `{BaseViewer, PDFThumbnailViewer}.setDocument` methods, but don't actually provide these errors to allow the viewer to handle them properly.
In practice this means that the GENERIC viewer won't display the `errorWrapper`, and in the MOZCENTRAL viewer the *browser* loading indicator is never hidden (since we never unblock the "load" event).
---
 web/app.js         | 27 +++++++++++++++++----------
 web/base_viewer.js | 16 ++++++++++------
 2 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/web/app.js b/web/app.js
index 1356ea627..704ac1b95 100644
--- a/web/app.js
+++ b/web/app.js
@@ -949,22 +949,22 @@ const PDFViewerApplication = {
       pdfDocument => {
         this.load(pdfDocument);
       },
-      exception => {
+      reason => {
         if (loadingTask !== this.pdfLoadingTask) {
           return undefined; // Ignore errors for previously opened PDF files.
         }
 
         let key = "loading_error";
-        if (exception instanceof InvalidPDFException) {
+        if (reason instanceof InvalidPDFException) {
           key = "invalid_file_error";
-        } else if (exception instanceof MissingPDFException) {
+        } else if (reason instanceof MissingPDFException) {
           key = "missing_file_error";
-        } else if (exception instanceof UnexpectedResponseException) {
+        } else if (reason instanceof UnexpectedResponseException) {
           key = "unexpected_response_error";
         }
         return this.l10n.get(key).then(msg => {
-          this._documentError(msg, { message: exception?.message });
-          throw exception;
+          this._documentError(msg, { message: reason?.message });
+          throw reason;
         });
       }
     );
@@ -1368,11 +1368,18 @@ const PDFViewerApplication = {
         });
     });
 
-    pagesPromise.then(() => {
-      this._unblockDocumentLoadEvent();
+    pagesPromise.then(
+      () => {
+        this._unblockDocumentLoadEvent();
 
-      this._initializeAutoPrint(pdfDocument, openActionPromise);
-    });
+        this._initializeAutoPrint(pdfDocument, openActionPromise);
+      },
+      reason => {
+        this.l10n.get("loading_error").then(msg => {
+          this._documentError(msg, { message: reason?.message });
+        });
+      }
+    );
 
     onePageRendered.then(data => {
       this.externalServices.reportTelemetry({
diff --git a/web/base_viewer.js b/web/base_viewer.js
index 3ea105873..931958ced 100644
--- a/web/base_viewer.js
+++ b/web/base_viewer.js
@@ -530,12 +530,14 @@ class BaseViewer {
       this.eventBus.dispatch("scrollmodechanged", { source: this, mode });
     }
 
-    this._pagesCapability.promise.then(() => {
-      this.eventBus.dispatch("pagesloaded", {
-        source: this,
-        pagesCount,
-      });
-    });
+    this._pagesCapability.promise.then(
+      () => {
+        this.eventBus.dispatch("pagesloaded", { source: this, pagesCount });
+      },
+      () => {
+        /* Prevent "Uncaught (in promise)"-messages in the console. */
+      }
+    );
 
     this._onBeforeDraw = evt => {
       const pageView = this._pages[evt.pageNumber - 1];
@@ -680,6 +682,8 @@ class BaseViewer {
       })
       .catch(reason => {
         console.error("Unable to initialize viewer", reason);
+
+        this._pagesCapability.reject(reason);
       });
   }