From 3b931fb0a67332973fb05e1db5bef262600922d8 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Tue, 7 Jul 2020 16:28:22 -0400
Subject: [PATCH 1/2] Add autoconf checks for all used core modules

---
 configure.ac | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/configure.ac b/configure.ac
index b4c2f77..94c0a7f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -39,6 +39,9 @@ AC_SUBST([PERL])
 m4_foreach_w([_m], [
     File::Basename
     File::Path
+    Getopt::Long
+    IO::Socket
+    Sys::Hostname
     version=0.77
   ], [AX_PROG_PERL_MODULES([_m], [],
          [AC_MSG_ERROR([missing required Perl module _m])])])

From 6ff0362450479eed5cfe3619d6c355b2060272a5 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Tue, 7 Jul 2020 20:42:40 -0400
Subject: [PATCH 2/2] Get the AF_INET and friends constants from Socket

Apparently it is enough to simply import Socket or IO::Socket to use
AF_INET and friends, but all examples in official documentation show
them in the import list. Because I do not fully understand the
intricacies of Perl import logic, I do the same thing here, fully
aware that I might have joined a cargo cult. Regardless of its
correctness or necessity, listing the constants in the import list has
the advantage of making it clear why the `use` statement exists.

I chose to import the constants from Socket instead of IO::Socket
because that module's documentation explicitly documents the
constants.
---
 configure.ac | 2 +-
 ddclient.in  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 94c0a7f..48616e1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -40,7 +40,7 @@ m4_foreach_w([_m], [
     File::Basename
     File::Path
     Getopt::Long
-    IO::Socket
+    Socket
     Sys::Hostname
     version=0.77
   ], [AX_PROG_PERL_MODULES([_m], [],
diff --git a/ddclient.in b/ddclient.in
index 0389ebc..776cb21 100755
--- a/ddclient.in
+++ b/ddclient.in
@@ -25,8 +25,8 @@ use warnings;
 use File::Basename;
 use File::Path qw(make_path);
 use Getopt::Long;
+use Socket qw(AF_INET AF_INET6 PF_INET PF_INET6);
 use Sys::Hostname;
-use IO::Socket;
 
 use version 0.77; our $VERSION = version->declare('v3.9.1');
 (my $version = $VERSION->stringify()) =~ s/^v//;