rule: never merge across non-expression statements

The existing logic can merge across non-expression statements,
if there is only one payload expression.

Example:
ether saddr 00:11:22:33:44:55 counter ether type 8021q

is turned into
counter ether saddr 00:11:22:33:44:55 ether type 8021q

which isn't the same thing.

Fix this up and add test cases for adjacent vlan and ip header
fields.  'Counter' serves as a non-merge fence.

Signed-off-by: Florian Westphal <fw@strlen.de>

1 files changed, 2 insertions, 4 deletions

diff --git a/src/rule.c b/src/rule.c
index 52c0672d..739b7a54 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -2744,10 +2744,8 @@ static void stmt_reduce(const struct rule *rule)
 
 		/* Must not merge across other statements */
 		if (stmt->ops->type != STMT_EXPRESSION) {
-			if (idx < 2)
-				continue;
-
-			payload_do_merge(sa, idx);
+			if (idx >= 2)
+				payload_do_merge(sa, idx);
 			idx = 0;
 			continue;
 		}