Commit 403dd2ee39 for ffmpeg

commit 403dd2ee396dbafc727fc7bf552ff41233811316
Author: Michael Niedermayer <michael@niedermayer.cc>
Date:   Sun Sep 20 00:04:04 2026 +0200

    avformat/dashdec: return EOF when a byte-range segment is exhausted

    Fixes: Timeout
    Fixes: t593bxSA0XOy
    Found during triage/review of the security report q8954W25MJoa
    Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
index ffef5bfb2f..f3985788f4 100644
--- a/libavformat/dashdec.c
+++ b/libavformat/dashdec.c
@@ -1747,8 +1747,11 @@ static int read_from_url(struct representation *pls, struct fragment *seg,
     int ret;

     /* limit read if the fragment was only a part of a file */
-    if (seg->size >= 0)
+    if (seg->size >= 0) {
         buf_size = FFMIN(buf_size, pls->cur_seg_size - pls->cur_seg_offset);
+        if (buf_size <= 0)
+            return AVERROR_EOF;
+    }

     ret = avio_read(pls->input, buf, buf_size);
     if (ret > 0)