[Qemu-devel] [PATCH] slirp: Gcc 9 -O3 fix

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

Gcc 9 needs some convincing that sopreprbuf really is going to fill
in iov in the call from soreadbuf, even though the failure case
shouldn't happen; so swing the check around initialising the fields.

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
 slirp/src/socket.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/slirp/src/socket.c b/slirp/src/socket.c
index 4a3c935e25..4a2222a95f 100644
--- a/slirp/src/socket.c
+++ b/slirp/src/socket.c
@@ -113,12 +113,14 @@ size_t sopreprbuf(struct socket *so, struct iovec *iov, 
int *np)
        DEBUG_CALL("sopreprbuf");
        DEBUG_ARG("so = %p", so);
 
-       if (len <= 0)
-               return 0;
-
        iov[0].iov_base = sb->sb_wptr;
+        iov[0].iov_len = 0;
         iov[1].iov_base = NULL;
         iov[1].iov_len = 0;
+
+       if (len <= 0)
+               return 0;
+
        if (sb->sb_wptr < sb->sb_rptr) {
                iov[0].iov_len = sb->sb_rptr - sb->sb_wptr;
                /* Should never succeed, but... */
-- 
2.21.0