lib: i_stream_read_more() - assert it can't return -2

diff --git a/src/lib/istream.h b/src/lib/istream.h
index 3c99bff641b8c1261189e606bd3cdce1d32e46c9..caed38b03adb2fcdfb76a5dc0bd970f8f5eed8a4 100644 (file)
--- a/src/lib/istream.h
+++ b/src/lib/istream.h
@@ -219,7 +219,9 @@ static inline int
 i_stream_read_more(struct istream *stream, const unsigned char **data_r,
                   size_t *size_r)
 {
-       return i_stream_read_bytes(stream, data_r, size_r, 1);
+       int ret = i_stream_read_bytes(stream, data_r, size_r, 1);
+       i_assert(ret != -2); /* stream must have space for at least 1 byte */
+       return ret;
 }
 /* Return the timestamp when istream last successfully read something.
    The timestamp is 0 if nothing has ever been read. */