Request unknown message indices

CMakeLists.txt

@@ -355,7 +355,7 @@ if(USE_BUNDLED_MTXCLIENT)
 	FetchContent_Declare(
 		MatrixClient
 		GIT_REPOSITORY https://github.com/Nheko-Reborn/mtxclient.git
-		GIT_TAG        v0.4.0
+		GIT_TAG        1e97d3195d366a15a086ca451d082d59972105ba
 		)
 	set(BUILD_LIB_EXAMPLES OFF CACHE INTERNAL "")
 	set(BUILD_LIB_TESTS OFF CACHE INTERNAL "")

io.github.NhekoReborn.Nheko.json

@@ -220,8 +220,7 @@
       "name": "mtxclient",
       "sources": [
         {
-          "commit": "2d6e3f79917ce2065a54ca32e6a9f9d42c0b6347",
-          "tag": "v0.4.0",
+          "commit": "1e97d3195d366a15a086ca451d082d59972105ba",
           "type": "git",
           "url": "https://github.com/Nheko-Reborn/mtxclient.git"
         }

src/Olm.cpp

@@ -890,12 +890,15 @@ decryptEvent(const MegolmSessionIndex &index,
         std::string msg_str;
         try {
                 auto session = cache::client()->getInboundMegolmSession(index);
+
                 auto res =
                   olm::client()->decrypt_group_message(session.get(), event.content.ciphertext);
                 msg_str = std::string((char *)res.data.data(), res.data.size());
         } catch (const lmdb::error &e) {
                 return {DecryptionErrorCode::DbError, e.what(), std::nullopt};
         } catch (const mtx::crypto::olm_exception &e) {
+                if (e.error_code() == mtx::crypto::OlmErrorCode::UNKNOWN_MESSAGE_INDEX)
+                        return {DecryptionErrorCode::MissingSessionIndex, e.what(), std::nullopt};
                 return {DecryptionErrorCode::DecryptionFailed, e.what(), std::nullopt};
         }
 

src/Olm.h

@@ -17,7 +17,9 @@ enum class DecryptionErrorCode
 {
         MissingSession, // Session was not found, retrieve from backup or request from other devices
                         // and try again
-        DbError,        // DB read failed
+        MissingSessionIndex, // Session was found, but it does not reach back enough to this index,
+                             // retrieve from backup or request from other devices and try again
+        DbError,            // DB read failed
         DecryptionFailed,   // libolm error
         ParsingFailed,      // Failed to parse the actual event
         ReplayAttack,       // Megolm index reused

src/timeline/EventStore.cpp

@@ -543,12 +543,21 @@ EventStore::decryptEvent(const IdIndex &idx,
 
         if (decryptionResult.error) {
                 switch (*decryptionResult.error) {
-                case olm::DecryptionErrorCode::MissingSession: {
-                        dummy.content.body =
-                          tr("-- Encrypted Event (No keys found for decryption) --",
-                             "Placeholder, when the message was not decrypted yet or can't be "
-                             "decrypted.")
-                            .toStdString();
+                case olm::DecryptionErrorCode::MissingSession:
+                case olm::DecryptionErrorCode::MissingSessionIndex: {
+                        if (decryptionResult.error == olm::DecryptionErrorCode::MissingSession)
+                                dummy.content.body =
+                                  tr("-- Encrypted Event (No keys found for decryption) --",
+                                     "Placeholder, when the message was not decrypted yet or can't "
+                                     "be "
+                                     "decrypted.")
+                                    .toStdString();
+                        else
+                                dummy.content.body =
+                                  tr("-- Encrypted Event (Key not valid for this index) --",
+                                     "Placeholder, when the message can't be decrypted with this "
+                                     "key since it is not valid for this index ")
+                                    .toStdString();
                         nhlog::crypto()->info("Could not find inbound megolm session ({}, {}, {})",
                                               index.room_id,
                                               index.session_id,