[Crypto] Improve Event.getClearContent() and fix assignement issue.

changelog.d/8744.bugfix

@@ -0,0 +1 @@
+Improve `Event.getClearContent()` and fix assignment issue that may help to decrypt last Event in the room list.

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/events/model/Event.kt

@@ -219,10 +219,16 @@ data class Event(
     }
 
     /**
-     * @return the event content
+     * @return the event content.
+     * If the content is encrypted, it will return the decrypted content, or null if the content is not
+     * decrypted.
      */
     fun getClearContent(): Content? {
-        return getDecryptedContent() ?: content
+        return if (isEncrypted()) {
+            getDecryptedContent()
+        } else {
+            content
+        }
     }
 
     /**

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/RustCryptoService.kt

@@ -627,7 +627,7 @@ internal class RustCryptoService @Inject constructor(
     }
 
     private fun notifyRoomKeyReceived(
-            roomId: String,
+            roomId: String?,
             sessionId: String,
     ) {
         megolmSessionImportManager.dispatchNewSession(roomId, sessionId)
@@ -664,18 +664,18 @@ internal class RustCryptoService @Inject constructor(
             when (event.type) {
                 EventType.ROOM_KEY -> {
                     val content = event.getClearContent().toModel<RoomKeyContent>() ?: return@forEach
-                    content.sessionKey
-                    val roomId = content.sessionId ?: return@forEach
-                    val sessionId = content.sessionId
+
+                    val roomId = content.roomId
+                    val sessionId = content.sessionId ?: return@forEach
 
                     notifyRoomKeyReceived(roomId, sessionId)
                     matrixConfiguration.cryptoAnalyticsPlugin?.onRoomKeyImported(sessionId, EventType.ROOM_KEY)
                 }
                 EventType.FORWARDED_ROOM_KEY -> {
                     val content = event.getClearContent().toModel<ForwardedRoomKeyContent>() ?: return@forEach
 
-                    val roomId = content.sessionId ?: return@forEach
-                    val sessionId = content.sessionId
+                    val roomId = content.roomId
+                    val sessionId = content.sessionId ?: return@forEach
 
                     notifyRoomKeyReceived(roomId, sessionId)
                     matrixConfiguration.cryptoAnalyticsPlugin?.onRoomKeyImported(sessionId, EventType.FORWARDED_ROOM_KEY)

matrix-sdk-android/src/test/java/org/matrix/android/sdk/internal/session/event/ValidDecryptedEventTest.kt

@@ -89,7 +89,7 @@ class ValidDecryptedEventTest {
                 ).toContent()
         )
 
-        val unValidatedContent = mixedEvent.getClearContent().toModel<MessageTextContent>()
+        val unValidatedContent = mixedEvent.content.toModel<MessageTextContent>()
         unValidatedContent?.body shouldBe "some message"
 
         mixedEvent.toValidDecryptedEvent()?.clearContent?.toModel<MessageTextContent>() shouldBe null