lib: Fixed istream_seekable.stat() to return correct size.

It was supposed to read until end of the stream, but it did it only when
stat() was called while stream was still fully in memory.

src/lib/istream-seekable.c

@@ -316,25 +316,24 @@ i_stream_seekable_stat(struct istream_private *stream, bool exact)
 		return 0;
 	}
 
-	if (sstream->membuf != NULL) {
-		/* we want to know the full size of the file, so read until
-		   we're finished */
-		old_offset = stream->istream.v_offset;
-		do {
-			i_stream_skip(&stream->istream,
-				      stream->pos - stream->skip);
-		} while ((ret = i_stream_seekable_read(stream)) > 0);
-
-		if (ret == 0) {
-			i_panic("i_stream_stat() used for non-blocking "
-				"seekable stream %s offset %"PRIuUOFF_T,
-				i_stream_get_name(sstream->cur_input),
-				sstream->cur_input->v_offset);
-		}
-		i_stream_skip(&stream->istream, stream->pos - stream->skip);
-		i_stream_seek(&stream->istream, old_offset);
-		unref_streams(sstream);
+	/* we want to know the full size of the file, so read until
+	   we're finished */
+	old_offset = stream->istream.v_offset;
+	do {
+		i_stream_skip(&stream->istream,
+			      stream->pos - stream->skip);
+	} while ((ret = i_stream_seekable_read(stream)) > 0);
+
+	if (ret == 0) {
+		i_panic("i_stream_stat() used for non-blocking "
+			"seekable stream %s offset %"PRIuUOFF_T,
+			i_stream_get_name(sstream->cur_input),
+			sstream->cur_input->v_offset);
 	}
+	i_stream_skip(&stream->istream, stream->pos - stream->skip);
+	i_stream_seek(&stream->istream, old_offset);
+	unref_streams(sstream);
+
 	if (stream->istream.stream_errno != 0)
 		return -1;