input/async: check for errors in Seek()

Fixes a busy loop in BufferingInputStream::RunThreadLocked() because the method never learns that seeking is ignored, even though the HTTP stream is already broken and can never be read; nobody cared to check for errors. Closes https://github.com/MusicPlayerDaemon/MPD/issues/1727

input/async: check for errors in Seek()
541468f0 · Max Kellermann · d2797eff · 541468f0 · 541468f0
Commit 541468f0 authored Jan 28, 2023 by Max Kellermann
Hide whitespace changes
Inline Side-by-side

Showing with 12 additions and 2 deletions

NEWS NEWS +2 -0

AsyncInputStream.cxx src/input/AsyncInputStream.cxx +10 -2

No files found.
--- a/NEWS
+++ b/NEWS
 ver 0.23.13 (not yet released)
+* input
+  - curl: fix busy loop after connection failed

 ver 0.23.12 (2023/01/17)
 * input

--- a/src/input/AsyncInputStream.cxx
+++ b/src/input/AsyncInputStream.cxx
@@ -101,9 +101,17 @@ AsyncInputStream::Seek(std::unique_lock<Mutex> &lock,
 	assert(IsReady());
 	assert(seek_state == SeekState::NONE);

-	if (new_offset == offset)
-		/* no-op */
+	if (new_offset == offset) {
+		/* no-op, but if the stream is not open anymore (maybe
+		   because it has failed), nothing can be read, so we
+		   should check for errors here instead of pretending
+		   everything's fine */
+
+		if (!open)
+			Check();
+
 		return;
+	}

 	if (!IsSeekable())
 		throw std::runtime_error("Not seekable");