Bug 1929105 - Automatically reload the displayed email message if reading an offline copy failed. r=aleca,BenC,KaiE

Depends on D228621.

Differential Revision: https://phabricator.services.mozilla.com/D228930

mail/base/content/aboutMessage.js

@@ -14,7 +14,7 @@
 
 // msgHdrView.js
 /* globals AdjustHeaderView ClearCurrentHeaders ClearPendingReadTimer
-   HideMessageHeaderPane OnLoadMsgHeaderPane OnTagsChange
+   HideMessageHeaderPane initFolderDBListener OnLoadMsgHeaderPane OnTagsChange
    OnUnloadMsgHeaderPane HandleAllAttachments AttachmentMenuController */
 
 var { MailServices } = ChromeUtils.importESModule(
@@ -203,6 +203,7 @@ function displayMessage(uri, viewWrapper) {
   const messageService = MailServices.messageServiceFromURI(uri);
   gMessage = messageService.messageURIToMsgHdr(uri);
   gFolder = gMessage.folder;
+  initFolderDBListener();
 
   messageHistory.push(uri);
 

mail/base/content/msgHdrView.js

@@ -222,6 +222,16 @@ class FolderDBListener {
     ) {
       updateStarButton();
     }
+
+    // If the offline flag gets removed, reload to download the message again.
+    // This could happen if the message's storeToken points to a bogus place in
+    // the message store.
+    if (
+      oldFlags & Ci.nsMsgMessageFlags.Offline &&
+      !(newFlags & Ci.nsMsgMessageFlags.Offline)
+    ) {
+      ReloadMessage();
+    }
   }
   onHdrDeleted() {}
   onHdrAdded() {}
@@ -1357,11 +1367,6 @@ function ClearCurrentHeaders() {
 function ShowMessageHeaderPane() {
   document.getElementById("msgHeaderView").collapsed = false;
   document.getElementById("mail-notification-top").collapsed = false;
-
-  // Initialize the DBListener if we don't have one. This might happen when the
-  // message pane is hidden or no message was selected before, which caused the
-  // clearing of the the DBListener.
-  initFolderDBListener();
 }
 
 function HideMessageHeaderPane() {

mail/base/test/browser/browser.ini

@@ -79,6 +79,7 @@ skip-if = os == 'mac'
 [browser_navigation.js]
 [browser_paneFocus.js]
 [browser_preferDisplayName.js]
+[browser_reloadBadMessage.js]
 [browser_repairFolder.js]
 [browser_quota.js]
 [browser_searchMessages.js]

mail/base/test/browser/browser_reloadBadMessage.js

@@ -0,0 +1,107 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Tests that a message with a bad storeToken is automatically reloaded and
+ * stored again.
+ */
+
+const { IMAPServer } = ChromeUtils.importESModule(
+  "resource://testing-common/IMAPServer.sys.mjs"
+);
+const { MessageGenerator } = ChromeUtils.importESModule(
+  "resource://testing-common/mailnews/MessageGenerator.sys.mjs"
+);
+
+let imapFolder;
+
+add_setup(async function () {
+  const generator = new MessageGenerator();
+
+  const account = MailServices.accounts.createLocalMailAccount();
+
+  const imapServer = new IMAPServer();
+  const imapAccount = MailServices.accounts.createAccount();
+  imapAccount.addIdentity(MailServices.accounts.createIdentity());
+  imapAccount.incomingServer = MailServices.accounts.createIncomingServer(
+    `${imapAccount.key}user`,
+    "localhost",
+    "imap"
+  );
+  imapAccount.incomingServer.port = imapServer.port;
+  imapAccount.incomingServer.username = "user";
+  imapAccount.incomingServer.password = "password";
+  const imapRootFolder = imapAccount.incomingServer.rootFolder;
+  imapFolder = imapRootFolder.getFolderWithFlags(Ci.nsMsgFolderFlags.Inbox);
+  await imapServer.addMessages(imapFolder, generator.makeMessages({}));
+
+  registerCleanupFunction(async () => {
+    await promiseServerIdle(imapAccount.incomingServer);
+    MailServices.accounts.removeAccount(account, false);
+    MailServices.accounts.removeAccount(imapAccount, false);
+  });
+});
+
+add_task(async function () {
+  const tabmail = document.getElementById("tabmail");
+  const about3Pane = tabmail.currentAbout3Pane;
+  const messagePaneBrowser =
+    about3Pane.messageBrowser.contentWindow.getMessagePaneBrowser();
+  about3Pane.restoreState({
+    folderURI: imapFolder.URI,
+    messagePaneVisible: true,
+  });
+
+  await BrowserTestUtils.waitForCondition(() => {
+    for (const m of imapFolder.messages) {
+      if (!(m.flags & Ci.nsMsgMessageFlags.Offline)) {
+        return false;
+      }
+    }
+    return true;
+  }, "waiting for message list to finish downloading");
+
+  let mboxSize = imapFolder.filePath.fileSize;
+  const messages = [...imapFolder.messages];
+  Assert.equal(messages[0].storeToken, "0", "first storeToken should be 0");
+  messages[0].storeToken = "1234"; // Much less than mboxSize.
+  messages[1].storeToken = "12345678"; // Much greater than mboxSize.
+  messages[2].storeToken = String(mboxSize - 2); // Near mboxSize, just in case.
+  messages[3].storeToken = String(mboxSize + 2);
+
+  for (let i = 0; i <= 3; i++) {
+    // Load the message. Attempting to load a message with a bad storeToken
+    // should cause it to be downloaded again from the server (you can verify
+    // this with MOZ_LOG=IMAP:4) and written to the mbox.
+    const loadedPromise = BrowserTestUtils.browserLoaded(
+      messagePaneBrowser,
+      false,
+      url => url.endsWith(messages[i].messageKey)
+    );
+    about3Pane.threadTree.selectedIndex = i;
+    await loadedPromise;
+
+    Assert.stringContains(
+      messagePaneBrowser.contentDocument.body.textContent,
+      "Hello " + messages[i].recipients.replace(/^"(.*)".*$/, "$1"),
+      "actual message content should load"
+    );
+    Assert.equal(
+      messages[i].storeToken,
+      String(mboxSize),
+      "message should have been rewritten at the end of the mbox file"
+    );
+    Assert.greater(
+      imapFolder.filePath.fileSize,
+      mboxSize,
+      "message should have been rewritten at the end of the mbox file"
+    );
+    Assert.ok(
+      messages[i].flags & Ci.nsMsgMessageFlags.Offline,
+      "message has regained the offline flag"
+    );
+
+    mboxSize = imapFolder.filePath.fileSize;
+  }
+});