From 2dcf1f7ed2601672e4081b6318334968fd7a9b68 Mon Sep 17 00:00:00 2001
From: Evil Eye <malusluminis@hotmail.com>
Date: Tue, 17 Sep 2024 20:56:04 +0200
Subject: [PATCH] Don't break the read_packet contract

---
 extern/osg-ffmpeg-videoplayer/videostate.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/extern/osg-ffmpeg-videoplayer/videostate.cpp b/extern/osg-ffmpeg-videoplayer/videostate.cpp
index 61e4f09cf3..158336784e 100644
--- a/extern/osg-ffmpeg-videoplayer/videostate.cpp
+++ b/extern/osg-ffmpeg-videoplayer/videostate.cpp
@@ -236,11 +236,17 @@ int VideoState::istream_read(void *user_data, uint8_t *buf, int buf_size)
         std::istream& stream = *static_cast<VideoState*>(user_data)->stream;
         stream.clear();
         stream.read((char*)buf, buf_size);
-        return stream.gcount();
+        if (stream.bad())
+            return AVERROR_UNKNOWN;
+        auto count = stream.gcount();
+        // avio_alloc_context says we mustn't return 0 for stream protocols
+        if (!count)
+            return AVERROR_EOF;
+        return count;
     }
     catch (std::exception& )
     {
-        return 0;
+        return AVERROR_UNKNOWN;
     }
 }