[libnftnl PATCH] rule: Don't append a newline when printing a rule

[Phil Sutter <phil@nwl.cc>]

Since commit c759027a526ac, printed rules may or may not end with a
newline depending on whether userdata was present or not. Deal with this
inconsistency by avoiding the trailing newline in all cases.

Fixes: c759027a526ac ("rule, set_elem: remove trailing \n in userdata snprintf")
Signed-off-by: Phil Sutter <phil@nwl.cc>
---
This supersedes the previous patch with subject: Partially revert "rule,
set_elem: remove trailing \n in userdata snprintf" by solving the
problem in the opposite direction. As correctly assessed by Pablo, this
way is consistent with other printers.

I tested the change with nftables and iptables testsuites. It breaks a
single test in the latter which compares full ruleset debug output
against a record. To fix that, one could just pass --ignore-blank-lines
parameter to the diff call.
---
 src/rule.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/rule.c b/src/rule.c
index 811d5a213f835..c22918a8f3527 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -573,23 +573,21 @@ static int nftnl_rule_snprintf_default(char *buf, size_t remain,
 		sep = " ";
 	}
 
-	ret = snprintf(buf + offset, remain, "\n");
-	SNPRINTF_BUFFER_SIZE(ret, remain, offset);
-
 	list_for_each_entry(expr, &r->expr_list, head) {
-		ret = snprintf(buf + offset, remain, "  [ %s ", expr->ops->name);
+		ret = snprintf(buf + offset, remain,
+			       "\n  [ %s ", expr->ops->name);
 		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
 
 		ret = nftnl_expr_snprintf(buf + offset, remain, expr,
 					     type, flags);
 		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
 
-		ret = snprintf(buf + offset, remain, "]\n");
+		ret = snprintf(buf + offset, remain, "]");
 		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
 	}
 
 	if (r->user.len) {
-		ret = snprintf(buf + offset, remain, "  userdata = { ");
+		ret = snprintf(buf + offset, remain, "\n  userdata = { ");
 		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
 
 		for (i = 0; i < r->user.len; i++) {
-- 
2.43.0