Bug 1633270 - view application/octet-stream PDFs in PDF.JS and add a pref to turn this off, r=jaws

Differential Revision: https://phabricator.services.mozilla.com/D75582

browser/app/profile/firefox.js

@@ -1372,6 +1372,9 @@ pref("pdfjs.firstRun", true);
 pref("pdfjs.previousHandler.preferredAction", 0);
 pref("pdfjs.previousHandler.alwaysAskBeforeHandling", false);
 
+// Try to convert PDFs sent as octet-stream
+pref("pdfjs.handleOctetStream", true);
+
 // Is the sidebar positioned ahead of the content browser
 pref("sidebar.position_start", true);
 

browser/extensions/pdfjs/components.conf

@@ -10,6 +10,8 @@ Classes = [
         'contract_ids': [
             '@mozilla.org/streamconv;1?from=application/pdf&to=*/*',
             '@mozilla.org/streamconv;1?from=application/pdf&to=text/html',
+            '@mozilla.org/streamconv;1?from=application/octet-stream&to=*/*',
+            '@mozilla.org/streamconv;1?from=application/octet-stream&to=text/html',
         ],
         'jsm': 'resource:///modules/pdfjs.js',
         'constructor': 'StreamConverterFactory',

browser/extensions/pdfjs/content/PdfStreamConverter.jsm

@@ -1031,6 +1031,13 @@ PdfStreamConverter.prototype = {
 
   // nsIStreamConverter::asyncConvertData
   asyncConvertData(aFromType, aToType, aListener, aCtxt) {
+    if (aCtxt && aCtxt instanceof Ci.nsIChannel) {
+      aCtxt.QueryInterface(Ci.nsIChannel);
+    }
+    // We need to check if we're supposed to convert here, because not all
+    // asyncConvertData consumers will call getConvertedType first:
+    this.getConvertedType(aFromType, aCtxt);
+
     // Store the listener passed to us
     this.listener = aListener;
   },
@@ -1109,13 +1116,32 @@ PdfStreamConverter.prototype = {
 
   getConvertedType(aFromType, aChannel) {
     const HTML = "text/html";
+    let channelURI = aChannel?.URI;
+    // We can be invoked for application/octet-stream; check if we want the
+    // channel first:
+    if (aFromType != "application/pdf") {
+      let isPDF = channelURI?.QueryInterface(Ci.nsIURL).fileExtension == "pdf";
+      let typeIsOctetStream = aFromType == "application/octet-stream";
+      if (
+        !isPDF ||
+        !typeIsOctetStream ||
+        !getBoolPref(PREF_PREFIX + ".handleOctetStream", false)
+      ) {
+        throw new Components.Exception(
+          "Ignore PDF.js for this download.",
+          Cr.NS_ERROR_FAILURE
+        );
+      }
+      // fall through, this appears to be a pdf.
+    }
+
     if (this._validateAndMaybeUpdatePDFPrefs()) {
       return HTML;
     }
     // Hm, so normally, no pdfjs. However... if this is a file: channel loaded
     // with system principal, load it anyway:
-    if (aChannel && aChannel.URI.schemeIs("file")) {
+    if (channelURI?.schemeIs("file")) {
-      let triggeringPrincipal = aChannel?.loadInfo?.triggeringPrincipal;
+      let triggeringPrincipal = aChannel.loadInfo?.triggeringPrincipal;
       if (triggeringPrincipal?.isSystemPrincipal) {
         return HTML;
       }

browser/extensions/pdfjs/test/browser.ini

@@ -6,6 +6,10 @@ support-files =
 [browser_pdfjs_force_opening_files.js]
 [browser_pdfjs_main.js]
 [browser_pdfjs_navigation.js]
+[browser_pdfjs_octet_stream.js]
+support-files =
+  file_pdfjs_object_stream.pdf
+  file_pdfjs_object_stream.pdf^headers^
 [browser_pdfjs_savedialog.js]
 skip-if = verify
 [browser_pdfjs_views.js]

browser/extensions/pdfjs/test/browser_pdfjs_octet_stream.js

@@ -0,0 +1,45 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const TESTROOT = getRootDirectory(gTestPath).replace(
+  "chrome://mochitests/content/",
+  "http://mochi.test:8888/"
+);
+
+/**
+ * Check that if we open a PDF with octet-stream mimetype, it can load
+ * PDF.js .
+ */
+add_task(async function test_octet_stream_opens_pdfjs() {
+  await SpecialPowers.pushPrefEnv({ set: [["pdfjs.handleOctetStream", true]] });
+  // Get a ref to the pdf we want to open.
+  let pdfURL = TESTROOT + "file_pdfjs_object_stream.pdf";
+
+  let mimeService = Cc["@mozilla.org/mime;1"].getService(Ci.nsIMIMEService);
+  let handlerInfo = mimeService.getFromTypeAndExtension(
+    "application/pdf",
+    "pdf"
+  );
+
+  // Make sure pdf.js is the default handler.
+  is(
+    handlerInfo.alwaysAskBeforeHandling,
+    false,
+    "pdf handler defaults to always-ask is false"
+  );
+  is(
+    handlerInfo.preferredAction,
+    Ci.nsIHandlerInfo.handleInternally,
+    "pdf handler defaults to internal"
+  );
+
+  await BrowserTestUtils.withNewTab(
+    { gBrowser, url: "about:blank" },
+    async function(newTabBrowser) {
+      await waitForPdfJS(newTabBrowser, pdfURL);
+      is(newTabBrowser.currentURI.spec, pdfURL, "Should load pdfjs");
+    }
+  );
+});

browser/extensions/pdfjs/test/file_pdfjs_object_stream.pdf^headers^

@@ -0,0 +1,2 @@
+Content-Type: application/octet-stream
+