From c712543ee57f1c76a925a04eba1b8356061d805b Mon Sep 17 00:00:00 2001
From: Oliver Jowett <oliver@mutability.co.uk>
Date: Mon, 8 Dec 2014 20:17:48 +0000
Subject: [PATCH] Only completeWrite() if we didn't run off the end of the
 buffer. If we did run off the end, complain about it.

---
 net_io.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net_io.c b/net_io.c
index 1da1dcb..c1b7b53 100644
--- a/net_io.c
+++ b/net_io.c
@@ -1196,7 +1196,11 @@ static void writeFATSV() {
         }
 
         p += snprintf(p, bufsize(p,end), "\n");
-        completeWrite(&Modes.fatsv_out, p);
+
+        if (p <= end)
+            completeWrite(&Modes.fatsv_out, p);
+        else
+            fprintf(stderr, "fatsv: output too large (max %d, overran by %d)\n", TSV_MAX_PACKET_SIZE, (int) (p - end));
 #       undef bufsize
 
         a->fatsv_last_emitted = now;