header filter istream: Fixed previosly added assert.

--HG--
branch : HEAD

diff --git a/src/lib-mail/istream-header-filter.c b/src/lib-mail/istream-header-filter.c
index ed8e821e40a11989ab76f71e723e9ae76bfc604d..b3e7b7e6b3d5788fc59d43ec09658ce5e48abb6c 100644 (file)
--- a/src/lib-mail/istream-header-filter.c
+++ b/src/lib-mail/istream-header-filter.c
@@ -246,7 +246,9 @@ static ssize_t read_header(struct header_filter_istream *mstream)
        mstream->istream.pos = pos;
 
        if (hdr_ret == 0) {
-               i_assert(ret > 0);
+               /* need more data to finish parsing headers. we may have some
+                  data already available though. */
+               i_assert(ret >= 0);
                return ret;
        }