From 04b02877388ae9b243ce3dfd62a61b6e543af152 Mon Sep 17 00:00:00 2001
From: Him188 <Him188@mamoe.net>
Date: Sun, 29 Mar 2020 12:41:07 +0800
Subject: [PATCH] Add pre-condition check

---
 .../jvmMain/kotlin/net/mamoe/mirai/message/SendImageUtilsJvm.kt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/message/SendImageUtilsJvm.kt b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/message/SendImageUtilsJvm.kt
index f045ac98f..31bfecdeb 100644
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/message/SendImageUtilsJvm.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/message/SendImageUtilsJvm.kt
@@ -116,7 +116,7 @@ suspend fun InputStream.uploadAsImage(contact: Contact): OfflineImage =
  */
 @Throws(OverFileSizeMaxException::class)
 suspend fun File.uploadAsImage(contact: Contact): OfflineImage {
-    require(this.exists() && this.canRead())
+    require(this.isFile && this.exists() && this.canRead()) { "file ${this.path} is not readable" }
     return withContext(Dispatchers.IO) { toExternalImage() }.upload(contact)
 }