上映会ニコニコ・バグ修正 (#358) (#359)

Reviewed-on: #359
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

frontend/src/pages/theatres/TheatreDetailPage.tsx

@@ -443,9 +443,13 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
     if (!(theatreInfo.postStartedAt))
       return
 
+    const currentVideoLength = videoLengthRef.current
+    if (currentVideoLength <= 0)
+      return
+
     const targetTime = Math.min (
 	currentPostElapsedMs (theatreInfo),
-	videoLength)
+	currentVideoLength)
 
     const drift = Math.abs (currentTimeMs - targetTime)
 
@@ -477,6 +481,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 	: 0
 
     setVideoLength (playableDurationMs)
+    videoLengthRef.current = playableDurationMs
 
     if (playableDurationMs <= 0)
       {