From: Miod Vallat <miod.vallat@powerdns.com>
Date: Fri, 25 Jul 2025 13:00:13 +0000 (+0200)
Subject: Do not use countLabels() in chopOff() loop conditions.
X-Git-Tag: auth-5.1.0-alpha0^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F15922%2Fhead;p=thirdparty%2Fpdns.git

Do not use countLabels() in chopOff() loop conditions.

Instead, compute it once outside of the loop in a local variable and
decrement that variable.

Signed-off-by: Miod Vallat <miod.vallat@powerdns.com>
---

diff --git a/pdns/dnsname.cc b/pdns/dnsname.cc
index 4316b3939..dcad68f93 100644
--- a/pdns/dnsname.cc
+++ b/pdns/dnsname.cc
@@ -632,8 +632,8 @@ unsigned int DNSName::countLabels() const
 
 void DNSName::trimToLabels(unsigned int to)
 {
-  while(countLabels() > to && chopOff()) {
-    ;
+  for (auto nlabels = countLabels(); nlabels > to; --nlabels) {
+    chopOff();
   }
 }
 
diff --git a/pdns/dnssecinfra.cc b/pdns/dnssecinfra.cc
index 53309fbc4..d6826db6c 100644
--- a/pdns/dnssecinfra.cc
+++ b/pdns/dnssecinfra.cc
@@ -526,7 +526,7 @@ string getMessageForRRSET(const DNSName& qname, const RRSIGRecordContent& rrc, c
 
     if (rrsig_labels < fqdn_labels) {
       DNSName choppedQname(qname);
-      while (choppedQname.countLabels() > rrsig_labels) {
+      for (auto nlabels = fqdn_labels; nlabels > rrsig_labels; --nlabels) {
         choppedQname.chopOff();
       }
       nameToHash = "\x01*" + choppedQname.toDNSStringLC();