Fix pipe_send() with no data

* libpipe/pipe.c (pipe_send): Set value pointed to by amount to 0 if
if nothing is written.

1 files changed, 4 insertions, 1 deletions

diff --git a/libpipe/pipe.c b/libpipe/pipe.c
index c3d2a28b..0b539218 100644
--- a/libpipe/pipe.c
+++ b/libpipe/pipe.c
@@ -319,7 +319,10 @@ pipe_send (struct pipe *pipe, int noblock, void *source,
 
   /* Nothing to do.  */
   if (data_len == 0 && control_len == 0 && num_ports == 0)
-    return 0;
+    {
+      *amount = 0;
+      return 0;
+    }
 
   err = pipe_wait_writable (pipe, noblock);
   if (err)