From 8c7a1b8a671291e6ee2e7e4abdbdd41e9c714b31 Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Thu, 6 Oct 2022 09:56:47 +0200
Subject: [PATCH] misc: Switch to a std::array in makeHexDump()

---
 pdns/misc.cc         | 10 +++++-----
 pdns/test-misc_hh.cc |  6 ++++++
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/pdns/misc.cc b/pdns/misc.cc
index f760a957ab..753821ccb7 100644
--- a/pdns/misc.cc
+++ b/pdns/misc.cc
@@ -583,13 +583,13 @@ string U32ToIP(uint32_t val)
 
 string makeHexDump(const string& str)
 {
-  char tmp[5];
+  std::array<char, 5> tmp;
   string ret;
-  ret.reserve((int)(str.size()*2.2));
+  ret.reserve(static_cast<size_t>(str.size()*2.2));
 
-  for(char n : str) {
-    snprintf(tmp, sizeof(tmp), "%02x ", (unsigned char)n);
-    ret+=tmp;
+  for (char n : str) {
+    snprintf(tmp.data(), tmp.size(), "%02x ", static_cast<unsigned char>(n));
+    ret += tmp.data();
   }
   return ret;
 }
diff --git a/pdns/test-misc_hh.cc b/pdns/test-misc_hh.cc
index f519048409..ec2f478f1f 100644
--- a/pdns/test-misc_hh.cc
+++ b/pdns/test-misc_hh.cc
@@ -391,4 +391,10 @@ BOOST_AUTO_TEST_CASE(test_makeBytesFromHex) {
   BOOST_CHECK_THROW(makeBytesFromHex("1234GG"), std::range_error);
 }
 
+BOOST_AUTO_TEST_CASE(test_makeHexDump) {
+  auto out = makeHexDump("\x12\x34\x56\x78\x90\xab\xcd\xef");
+  // there is a trailing white space by design
+  BOOST_CHECK_EQUAL(out, "12 34 56 78 90 ab cd ef ");
+}
+
 BOOST_AUTO_TEST_SUITE_END()
-- 
2.47.2