From 775d45b36ac6b75795f55c143e21034ff4370a9a Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sat, 2 Jan 2021 12:02:58 +0100
Subject: [PATCH] Remove the `DownloadManager.onerror` functionality, since its
 only usage is unlikely to be helpful

Note how the `onerror` functionality is not being used in the GENERIC `DownloadManager`, since we have no way of knowing if downloading succeeded.
Hence this functionality is only *possibly* useful in MOZCENTRAL builds, however as outlined in the existing comments it's unlikely to be helpful in practice. Generally speaking, if downloading failed once in [`PdfStreamConverter.jsm`](https://searchfox.org/mozilla-central/rev/809ac3660845fef6faf18ec210232fdadc0f1ad9/toolkit/components/pdfjs/content/PdfStreamConverter.jsm#294-406) it seems very likely that it would fail again; all-in-all I'm thus suggesting that we just remove the `onerror` functionality altogether here.
---
 web/app.js              | 10 ----------
 web/download_manager.js |  1 -
 web/firefoxcom.js       |  6 ++++--
 3 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/web/app.js b/web/app.js
index 2166e8f21..1c44dc548 100644
--- a/web/app.js
+++ b/web/app.js
@@ -993,11 +993,6 @@ const PDFViewerApplication = {
     const downloadManager = this.downloadManager,
       url = this.baseUrl,
       filename = this._docFilename;
-    downloadManager.onerror = err => {
-      // This error won't really be helpful because it's likely the
-      // fallback won't work either (or is already open).
-      this.error(`PDF failed to download: ${err}`);
-    };
 
     // When the PDF document isn't ready, or the PDF file is still downloading,
     // simply download using the URL.
@@ -1023,11 +1018,6 @@ const PDFViewerApplication = {
     const downloadManager = this.downloadManager,
       url = this.baseUrl,
       filename = this._docFilename;
-    downloadManager.onerror = err => {
-      // This error won't really be helpful because it's likely the
-      // fallback won't work either (or is already open).
-      this.error(`PDF failed to be saved: ${err}`);
-    };
 
     // When the PDF document isn't ready, or the PDF file is still downloading,
     // simply download using the URL.
diff --git a/web/download_manager.js b/web/download_manager.js
index 3c287f856..0261e4580 100644
--- a/web/download_manager.js
+++ b/web/download_manager.js
@@ -71,7 +71,6 @@ class DownloadManager {
       this.downloadUrl(url, filename);
       return;
     }
-
     const blobUrl = URL.createObjectURL(blob);
     download(blobUrl, filename);
   }
diff --git a/web/firefoxcom.js b/web/firefoxcom.js
index afca70122..5ea019c61 100644
--- a/web/firefoxcom.js
+++ b/web/firefoxcom.js
@@ -130,8 +130,10 @@ class DownloadManager {
       filename,
       sourceEventType,
     }).then(error => {
-      if (error && this.onerror) {
-        this.onerror(error);
+      if (error) {
+        // If downloading failed in `PdfStreamConverter.jsm` it's very unlikely
+        // that attempting to fallback and re-download would be helpful here.
+        console.error("`ChromeActions.download` failed.");
       }
       URL.revokeObjectURL(blobUrl);
     });