[PATCH] tcp: Suppress new instance of cppcheck bug 14191

[David Gibson <david@gibson.dropbear.id.au>]

From: Laurent Vivier <lvivier@redhat.com>

ee9b2361d ("cppcheck: Suppress a buggy cppcheck warning") added a
a suppression for a cppchec bug, since filed (and fixed) in upstream
cppcheck as https://trac.cppcheck.net/ticket/14191.  9139e60fd ("tcp:
Acknowledge everything if it looks like bulk traffic, not interactive")
introduced a new point which triggers the same cppcheck bug.

Add a suppression for the new instance.  This is a revision of Laurent's
earlier patch, updating the comments to make the connection between the
two instances clear, and adding unmatchedSuppression so it doesn't cause
a bogus warning with unaffected cppcheck versions.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 tcp.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/tcp.c b/tcp.c
index 7c721b4b..1711bcc7 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1132,6 +1132,11 @@ int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
 				return 0;
 		}
 
+		/* This trips a cppcheck bug in some versions, including
+		 * cppcheck 2.18.3.
+		 * https://trac.cppcheck.net/ticket/14191
+		 */
+		/* cppcheck-suppress [uninitvar,unmatchedSuppression] */
 		if ((unsigned)SNDBUF_GET(conn) > (long long)tinfo->tcpi_rtt *
 						 tinfo->tcpi_delivery_rate /
 						 1000 / 1000 *
@@ -1143,10 +1148,7 @@ int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
 		/* Fall back to acknowledging everything we got */
 		conn->seq_ack_to_tap = conn->seq_from_tap;
 	} else {
-		/* This trips a cppcheck bug in some versions, including
-		 * cppcheck 2.18.3.
-		 * https://sourceforge.net/p/cppcheck/discussion/general/thread/fecde59085/
-		 */
+		/* cppcheck bug 14191 again, see above */
 		/* cppcheck-suppress [uninitvar,unmatchedSuppression] */
 		conn->seq_ack_to_tap = tinfo->tcpi_bytes_acked +
 		                       conn->seq_init_from_tap;
-- 
2.52.0