fix: key uploads only running once

There were several issues here. Key uploads in general failed, because
the await caused a Future<dynamic> to be returned, which failed type
checking.

But also we never unset our future, which was used for the online key
backup uploads, which meant we would very quickly stop uploading any
keys at all.

lib/encryption/encryption.dart

@@ -232,9 +232,12 @@ class Encryption {
         // the entry should always exist. In the case it doesn't, the following
         // line *could* throw an error. As that is a future, though, and we call
         // it un-awaited here, nothing happens, which is exactly the result we want
+        client.database
             // ignore: discarded_futures
-        client.database?.updateInboundGroupSessionIndexes(
-            json.encode(inboundGroupSession.indexes), roomId, sessionId);
+            ?.updateInboundGroupSessionIndexes(
+                json.encode(inboundGroupSession.indexes), roomId, sessionId)
+            // ignore: discarded_futures
+            .onError((e, _) => Logs().e('Ignoring error for updating indexes'));
       }
       decryptedPayload = json.decode(decryptResult.plaintext);
     } catch (exception) {

lib/encryption/key_manager.dart

@@ -795,13 +795,18 @@ class KeyManager {
     // Make sure to not run in parallel
     if (_uploadingFuture != null) {
       if (skipIfInProgress) return;
-      await _uploadingFuture;
-    }
-    final completer = Completer<void>();
-    _uploadingFuture = completer.future;
-
-    await client.userDeviceKeysLoading;
       try {
+        await _uploadingFuture;
+      } finally {
+        // shouldn't be necessary, since it will be unset already by the other process that started it, but just to be safe, also unset the future here
+        _uploadingFuture = null;
+      }
+    }
+
+    Future<void> uploadInternal() async {
+      try {
+        await client.userDeviceKeysLoading;
+
         if (!(await isCached())) {
           return; // we can't backup anyways
         }
@@ -821,6 +826,7 @@ class KeyManager {
           if (info.algorithm !=
                   BackupAlgorithm.mMegolmBackupV1Curve25519AesSha2 ||
               info.authData['public_key'] != backupPubKey) {
+            decryption.free();
             return;
           }
           final args = GenerateUploadKeysArgs(
@@ -861,8 +867,14 @@ class KeyManager {
         }
       } catch (e, s) {
         Logs().e('[Key Manager] Error uploading room keys', e, s);
+      }
+    }
+
+    _uploadingFuture = uploadInternal();
+    try {
+      await _uploadingFuture;
     } finally {
-      completer.complete();
+      _uploadingFuture = null;
     }
   }
 
@@ -1187,12 +1199,12 @@ RoomKeys generateUploadKeysImplementation(GenerateUploadKeysArgs args) {
         },
       );
     }
+    enc.free();
     return roomKeys;
   } catch (e, s) {
     Logs().e('[Key Manager] Error generating payload', e, s);
-    rethrow;
-  } finally {
     enc.free();
+    rethrow;
   }
 }
 

lib/src/utils/native_implementations.dart

@@ -52,7 +52,7 @@ abstract class NativeImplementations {
 
   /// this implementation will catch any non-implemented method
   @override
-  dynamic noSuchMethod(Invocation invocation) async {
+  dynamic noSuchMethod(Invocation invocation) {
     final dynamic argument = invocation.positionalArguments.single;
     final memberName = invocation.memberName.toString().split('"')[1];
 
@@ -62,11 +62,15 @@ abstract class NativeImplementations {
       'Fallback from NativeImplementations.dummy used.',
     );
     switch (memberName) {
+      // we need to pass the futures right through or we will run into type errors later!
       case 'generateUploadKeys':
+        // ignore: discarded_futures
         return dummy.generateUploadKeys(argument);
       case 'keyFromPassphrase':
+        // ignore: discarded_futures
         return dummy.keyFromPassphrase(argument);
       case 'decryptFile':
+        // ignore: discarded_futures
         return dummy.decryptFile(argument);
       case 'shrinkImage':
         return dummy.shrinkImage(argument);