Fix banned mime type errors in DefaultContentScannerService (#7255)

The content scanner allows disabling certain mime types for files in the set up HS, but it turns out for the scan operation instead of returning an `"is_valid": false` result in that case, it returns an error with a `MCS_MIME_TYPE_FORBIDDEN` reason. We need to handle that case as if it had returned the false `isValid` value.

features/contentscanner/impl/src/main/kotlin/io/element/android/features/contentscanner/impl/DefaultContentScannerService.kt

@@ -10,6 +10,7 @@ package io.element.android.features.contentscanner.impl
 import io.element.android.features.contentscanner.api.ContentScannerService
 import io.element.android.libraries.core.coroutine.CoroutineDispatchers
 import io.element.android.libraries.matrix.api.core.EventId
+import io.element.android.libraries.matrix.api.exception.ClientException
 import io.element.android.libraries.matrix.api.media.MediaSource
 import io.element.android.libraries.matrix.api.scanner.ContentScanner
 import io.element.android.libraries.matrix.ui.media.contentvalidation.ContentValidationState
@@ -42,10 +43,16 @@ class DefaultContentScannerService(
                         contentValidationState.update(url, contentValidationValue)
                     }
                     .onFailure { exception ->
-                        if (exception is IOException) {
+                        when (exception) {
+                            is IOException -> {
                                 // If it's an IO-related exception, we can retry later, so we don't store the error
                                 contentValidationState.update(url, ContentValidationValue.Unknown)
-                        } else {
+                            }
+                            is ClientException.ContentScanner if exception.reason.isDangerous() -> {
+                                // It's a dangerous content (banned mime-type?), we mark it as invalid
+                                contentValidationState.update(url, ContentValidationValue.Invalid)
+                            }
+                            else -> {
                                 // For other exceptions, we cache the failure
                                 contentValidationState.update(url, ContentValidationValue.UnrecoverableError(exception))
                             }
@@ -54,3 +61,4 @@ class DefaultContentScannerService(
             }
         }
     }
+}

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/scanner/RustContentScanner.kt

@@ -7,9 +7,11 @@
 
 package io.element.android.libraries.matrix.impl.scanner
 
+import io.element.android.libraries.core.extensions.mapFailure
 import io.element.android.libraries.core.extensions.runCatchingExceptions
 import io.element.android.libraries.matrix.api.media.MediaSource
 import io.element.android.libraries.matrix.api.scanner.ContentScanner
+import io.element.android.libraries.matrix.impl.exception.mapClientException
 import org.matrix.rustcomponents.sdk.Client
 import org.matrix.rustcomponents.sdk.NoHandle
 import org.matrix.rustcomponents.sdk.ContentScanner as RustScanner
@@ -22,6 +24,8 @@ class RustContentScanner(
     override suspend fun scan(mediaSource: MediaSource): Result<Boolean> {
         return runCatchingExceptions {
             rustScanner.scan(client, mediaSource.toRustMediaSource()).clean
+        }.mapFailure {
+            it.mapClientException()
         }
     }
 }