input/icy: adjust offset at end of stream in Read()

ProxyInputStream::Read() assigns the `offset` field, which is the
wrong offset because it does not consider Icy metadata removed from
the stream.  Therefore, after every ProxyInputStream::Read() call,
IcyInputStream::Read() needs to override this offset.  This was
missing at the end of the stream, when Read()==0.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1216

NEWS

@@ -3,6 +3,8 @@ ver 0.22.10 (not yet released)
   - support "albumart" for virtual tracks in CUE sheets
 * database
   - simple: fix crash bug
+* input
+  - curl: fix crash bug after stream with Icy metadata was closed by peer
 
 ver 0.22.9 (2021/06/23)
 * database

src/input/IcyInputStream.cxx

@@ -104,8 +104,11 @@ IcyInputStream::Read(std::unique_lock<Mutex> &lock,
 
 	while (true) {
 		size_t nbytes = ProxyInputStream::Read(lock, ptr, read_size);
-		if (nbytes == 0)
+		if (nbytes == 0) {
+			assert(IsEOF());
+			offset = override_offset;
 			return 0;
+		}
 
 		size_t result = parser->ParseInPlace(ptr, nbytes);
 		if (result > 0) {