Fix crash when creating link to room preview

src/Cache.cpp

@@ -3006,49 +3006,54 @@ Cache::getMember(const std::string &room_id, const std::string &user_id)
 std::vector<RoomMember>
 Cache::getMembers(const std::string &room_id, std::size_t startIndex, std::size_t len)
 {
-    auto txn    = ro_txn(env_);
+    try {
-    auto db     = getMembersDb(txn, room_id);
+        auto txn    = ro_txn(env_);
-    auto cursor = lmdb::cursor::open(txn, db);
+        auto db     = getMembersDb(txn, room_id);
+        auto cursor = lmdb::cursor::open(txn, db);
 
-    std::size_t currentIndex = 0;
+        std::size_t currentIndex = 0;
 
-    const auto endIndex = std::min(startIndex + len, db.size(txn));
+        const auto endIndex = std::min(startIndex + len, db.size(txn));
 
-    std::vector<RoomMember> members;
+        std::vector<RoomMember> members;
+
+        std::string_view user_id, user_data;
+        while (cursor.get(user_id, user_data, MDB_NEXT)) {
+            if (currentIndex < startIndex) {
+                currentIndex += 1;
+                continue;
+            }
+
+            if (currentIndex >= endIndex)
+                break;
+
+            try {
+                MemberInfo tmp = nlohmann::json::parse(user_data).get<MemberInfo>();
+                members.emplace_back(RoomMember{QString::fromStdString(std::string(user_id)),
+                                                QString::fromStdString(tmp.name)});
+            } catch (const nlohmann::json::exception &e) {
+                nhlog::db()->warn("{}", e.what());
+            }
 
-    std::string_view user_id, user_data;
-    while (cursor.get(user_id, user_data, MDB_NEXT)) {
-        if (currentIndex < startIndex) {
             currentIndex += 1;
-            continue;
         }
 
-        if (currentIndex >= endIndex)
+        cursor.close();
-            break;
 
-        try {
+        return members;
-            MemberInfo tmp = nlohmann::json::parse(user_data).get<MemberInfo>();
+    } catch (const lmdb::error &e) {
-            members.emplace_back(RoomMember{QString::fromStdString(std::string(user_id)),
+        nhlog::db()->error("Failed to retrieve members from db in room {}: {}", room_id, e.what());
-                                            QString::fromStdString(tmp.name)});
+        return {};
-        } catch (const nlohmann::json::exception &e) {
-            nhlog::db()->warn("{}", e.what());
-        }
-
-        currentIndex += 1;
     }
-
-    cursor.close();
-
-    return members;
 }
 
 std::vector<RoomMember>
 Cache::getMembersFromInvite(const std::string &room_id, std::size_t startIndex, std::size_t len)
 {
-    auto txn = ro_txn(env_);
-    std::vector<RoomMember> members;
-
     try {
+        auto txn = ro_txn(env_);
+        std::vector<RoomMember> members;
+
         auto db     = getInviteMembersDb(txn, room_id);
         auto cursor = lmdb::cursor::open(txn, db);
 
@@ -3079,11 +3084,12 @@ Cache::getMembersFromInvite(const std::string &room_id, std::size_t startIndex,
         }
 
         cursor.close();
-    } catch (const lmdb::error &e) {
-        nhlog::db()->warn("Failed to retrieve members {}", e.what());
-    }
 
-    return members;
+        return members;
+    } catch (const lmdb::error &e) {
+        nhlog::db()->error("Failed to retrieve members from db in room {}: {}", room_id, e.what());
+        return {};
+    }
 }
 
 bool
@@ -4033,17 +4039,22 @@ Cache::roomMembers(const std::string &room_id)
 {
     auto txn = ro_txn(env_);
 
-    std::vector<std::string> members;
+    try {
-    std::string_view user_id, unused;
+        std::vector<std::string> members;
+        std::string_view user_id, unused;
 
-    auto db = getMembersDb(txn, room_id);
+        auto db = getMembersDb(txn, room_id);
 
-    auto cursor = lmdb::cursor::open(txn, db);
+        auto cursor = lmdb::cursor::open(txn, db);
-    while (cursor.get(user_id, unused, MDB_NEXT))
+        while (cursor.get(user_id, unused, MDB_NEXT))
-        members.emplace_back(user_id);
+            members.emplace_back(user_id);
-    cursor.close();
+        cursor.close();
 
-    return members;
+        return members;
+    } catch (const lmdb::error &e) {
+        nhlog::db()->error("Failed to retrieve members from db in room {}: {}", room_id, e.what());
+        return {};
+    }
 }
 
 crypto::Trust

src/Utils.cpp

@@ -881,3 +881,63 @@ utils::markRoomAsDirect(QString roomid, std::vector<RoomMember> members)
           });
       });
 }
+
+std::vector<std::string>
+utils::roomVias(const std::string &roomid)
+{
+    std::vector<std::string> vias;
+
+    {
+        auto members = cache::getMembers(roomid, 0, 100);
+        if (!members.empty()) {
+            vias.push_back(http::client()->user_id().hostname());
+            for (const auto &m : members) {
+                if (vias.size() >= 4)
+                    break;
+
+                auto user_id =
+                  mtx::identifiers::parse<mtx::identifiers::User>(m.user_id.toStdString());
+
+                auto server = user_id.hostname();
+                if (std::find(begin(vias), end(vias), server) == vias.end())
+                    vias.push_back(server);
+            }
+        }
+    }
+
+    if (vias.empty()) {
+        auto members = cache::getMembersFromInvite(roomid, 0, 100);
+        if (!members.empty()) {
+            vias.push_back(http::client()->user_id().hostname());
+            for (const auto &m : members) {
+                if (vias.size() >= 4)
+                    break;
+
+                auto user_id =
+                  mtx::identifiers::parse<mtx::identifiers::User>(m.user_id.toStdString());
+
+                auto server = user_id.hostname();
+                if (std::find(begin(vias), end(vias), server) == vias.end())
+                    vias.push_back(server);
+            }
+        }
+    }
+
+    if (vias.empty()) {
+        auto parents = cache::client()->getParentRoomIds(roomid);
+        for (const auto &p : parents) {
+            auto child =
+              cache::client()->getStateEvent<mtx::events::state::space::Child>(p, roomid);
+            if (child && child->content.via)
+                vias.insert(vias.end(), child->content.via->begin(), child->content.via->end());
+        }
+
+        std::sort(begin(vias), end(vias));
+        auto last = std::unique(begin(vias), end(vias));
+        vias.erase(last, end(vias));
+
+        // if (vias.size()> 3)
+        //     vias.erase(begin(vias)+3, end(vias));
+    }
+    return vias;
+}

src/Utils.h

@@ -311,4 +311,7 @@ removeDirectFromRoom(QString roomid);
 
 void
 markRoomAsDirect(QString roomid, std::vector<RoomMember> members);
+
+std::vector<std::string>
+roomVias(const std::string &roomid);
 }

src/timeline/RoomlistModel.cpp

@@ -645,15 +645,8 @@ void
 RoomlistModel::joinPreview(QString roomid)
 {
     if (previewedRooms.contains(roomid)) {
-        std::vector<std::string> vias;
+        ChatPage::instance()->joinRoomVia(
-        auto parents = cache::client()->getParentRoomIds(roomid.toStdString());
+          roomid.toStdString(), utils::roomVias(roomid.toStdString()), false);
-        for (const auto &p : parents) {
-            auto child = cache::client()->getStateEvent<mtx::events::state::space::Child>(
-              p, roomid.toStdString());
-            if (child && child->content.via)
-                vias.insert(vias.end(), child->content.via->begin(), child->content.via->end());
-        }
-        ChatPage::instance()->joinRoomVia(roomid.toStdString(), vias, false);
     }
 }
 void

src/timeline/TimelineModel.cpp

@@ -1813,16 +1813,12 @@ TimelineModel::getRoomVias(const QString &roomId)
 {
     QStringList vias;
 
-    vias.push_back(QStringLiteral("via=%1").arg(QString(
+    for (const auto &m : utils::roomVias(roomId.toStdString())) {
-      QUrl::toPercentEncoding(QString::fromStdString(http::client()->user_id().hostname())))));
-    auto members = cache::getMembers(roomId.toStdString(), 0, 100);
-    for (const auto &m : members) {
         if (vias.size() >= 4)
             break;
 
-        auto user_id   = mtx::identifiers::parse<mtx::identifiers::User>(m.user_id.toStdString());
+        QString server =
-        QString server = QStringLiteral("via=%1").arg(
+          QStringLiteral("via=%1").arg(QString(QUrl::toPercentEncoding(QString::fromStdString(m))));
-          QString(QUrl::toPercentEncoding(QString::fromStdString(user_id.hostname()))));
 
         if (!vias.contains(server))
             vias.push_back(server);