From 53cca5a743b79ca4374d60185983a5f0f9b04b63 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Wed, 16 Jun 2021 01:28:36 -0400
Subject: [PATCH] PadMessageHandler: Also send `USER_NEWINFO` messages on
 reconnect

Now the user list is correct after a reconnect. This also allows
ep_webrtc to automatically recover after a temporary network glitch.
---
 src/node/handler/PadMessageHandler.js | 103 ++++++++++++--------------
 1 file changed, 46 insertions(+), 57 deletions(-)

diff --git a/src/node/handler/PadMessageHandler.js b/src/node/handler/PadMessageHandler.js
index 899991a11..a1194ea91 100644
--- a/src/node/handler/PadMessageHandler.js
+++ b/src/node/handler/PadMessageHandler.js
@@ -1121,72 +1121,61 @@ const handleClientReady = async (socket, message, authorID) => {
 
     // Save the current revision in sessioninfos, should be the same as in clientVars
     sessionInfo.rev = pad.getHeadRevisionNumber();
+  }
 
-    // prepare the notification for the other users on the pad, that this user joined
-    const messageToTheOtherUsers = {
+  // Notify other users about this new user.
+  socket.broadcast.to(padIds.padId).json.send({
+    type: 'COLLABROOM',
+    data: {
+      type: 'USER_NEWINFO',
+      userInfo: {
+        colorId: authorColorId,
+        name: authorName,
+        userId: authorID,
+      },
+    },
+  });
+
+  // Notify this new user about other users.
+  await Promise.all(_getRoomSockets(pad.id).map(async (roomSocket) => {
+    if (roomSocket.id === socket.id) return;
+
+    // sessioninfos might change while enumerating, so check if the sessionID is still assigned to a
+    // valid session.
+    const sessionInfo = sessioninfos[roomSocket.id];
+    if (sessionInfo == null) return;
+
+    // get the authorname & colorId
+    const authorId = sessionInfo.author;
+    // The authorId of this other user might be unknown if the other user just connected and has
+    // not yet sent a CLIENT_READY message.
+    if (authorId == null) return;
+
+    // reuse previously created cache of author's data
+    const authorInfo = historicalAuthorData[authorId] || await authorManager.getAuthor(authorId);
+    if (authorInfo == null) {
+      messageLogger.error(
+          `Author ${authorId} connected via socket.io session ${roomSocket.id} is missing from ` +
+            'the global author database. This should never happen because the author ID is ' +
+            'generated by the same code that adds the author to the database.');
+      // Don't bother telling the new user about this mystery author.
+      return;
+    }
+
+    const msg = {
       type: 'COLLABROOM',
       data: {
         type: 'USER_NEWINFO',
         userInfo: {
-          colorId: authorColorId,
-          userId: authorID,
+          colorId: authorInfo.colorId,
+          name: authorInfo.name,
+          userId: authorId,
         },
       },
     };
 
-    // Add the authorname of this new User, if avaiable
-    if (authorName != null) {
-      messageToTheOtherUsers.data.userInfo.name = authorName;
-    }
-
-    // notify all existing users about new user
-    socket.broadcast.to(padIds.padId).json.send(messageToTheOtherUsers);
-
-    // Get sessions for this pad and update them (in parallel)
-    await Promise.all(_getRoomSockets(pad.id).map(async (roomSocket) => {
-      // Jump over, if this session is the connection session
-      if (roomSocket.id === socket.id) {
-        return;
-      }
-
-      // Since sessioninfos might change while being enumerated, check if the
-      // sessionID is still assigned to a valid session
-      const sessionInfo = sessioninfos[roomSocket.id];
-      if (sessionInfo == null) return;
-
-      // get the authorname & colorId
-      const authorId = sessionInfo.author;
-      // The authorId of this other user might be unknown if the other user just connected and has
-      // not yet sent a CLIENT_READY message.
-      if (authorId == null) return;
-
-      // reuse previously created cache of author's data
-      const authorInfo = historicalAuthorData[authorId] || await authorManager.getAuthor(authorId);
-      if (authorInfo == null) {
-        messageLogger.error(
-            `Author ${authorId} connected via socket.io session ${roomSocket.id} is missing from ` +
-            'the global author database. This should never happen because the author ID is ' +
-            'generated by the same code that adds the author to the database.');
-        // Don't bother telling the new user about this mystery author.
-        return;
-      }
-
-      // Send the new User a Notification about this other user
-      const msg = {
-        type: 'COLLABROOM',
-        data: {
-          type: 'USER_NEWINFO',
-          userInfo: {
-            colorId: authorInfo.colorId,
-            name: authorInfo.name,
-            userId: authorId,
-          },
-        },
-      };
-
-      socket.json.send(msg);
-    }));
-  }
+    socket.json.send(msg);
+  }));
 };
 
 /**