From e37ad765c86d2a763a2d655068dfe59789f18e3e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Thu, 2 Dec 2021 11:29:45 +0100
Subject: [PATCH] meson: disallow the combination of cryptolib=openssl and
 dns-over-tls=gnutls

It could work, but it doesn't make much sense. If we already have openssl as
the cryptolib that provides the necessary support, let's not bring in another
library. Disallowing this simplifies things and reduces our support matrix.
---
 meson.build | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/meson.build b/meson.build
index 968d752fde..4cc97d664e 100644
--- a/meson.build
+++ b/meson.build
@@ -1448,9 +1448,25 @@ else
 endif
 conf.set10('HAVE_DBUS', have)
 
+# We support one or the other. If gcrypt is available, we assume it's there to
+# be used, and use it in preference.
+opt = get_option('cryptolib')
+if opt == 'openssl' and conf.get('HAVE_OPENSSL') == 0
+        error('openssl requested as the default cryptolib, but not available')
+endif
+conf.set10('PREFER_OPENSSL',
+           opt == 'openssl' or (opt == 'auto' and conf.get('HAVE_OPENSSL') == 1 and conf.get('HAVE_GCRYPT') == 0))
+conf.set10('HAVE_OPENSSL_OR_GCRYPT',
+           conf.get('HAVE_OPENSSL') == 1 or conf.get('HAVE_GCRYPT') == 1)
+lib_openssl_or_gcrypt = conf.get('PREFER_OPENSSL') == 1 ? libopenssl : libgcrypt
+
 dns_over_tls = get_option('dns-over-tls')
 if dns_over_tls != 'false'
-        if dns_over_tls == 'openssl'
+        if dns_over_tls == 'gnutls' and conf.get('PREFER_OPENSSL') == 1
+                error('Sorry, -Ddns-over-tls=gnutls is not supported when openssl is used as the cryptolib')
+        endif
+
+        if dns_over_tls == 'openssl' or conf.get('PREFER_OPENSSL') == 1
                 have_gnutls = false
         else
                 have_gnutls = (conf.get('HAVE_GNUTLS') == 1 and libgnutls.version().version_compare('>= 3.6.0'))
@@ -1511,18 +1527,6 @@ else
 endif
 conf.set10('ENABLE_REPART', have)
 
-# We support one or the other. If gcrypt is available, we assume it's there to
-# be used, and use it in preference.
-opt = get_option('cryptolib')
-if opt == 'openssl' and conf.get('HAVE_OPENSSL') == 0
-        error('openssl requested as the default cryptolib, but not available')
-endif
-conf.set10('PREFER_OPENSSL',
-           opt == 'openssl' or (opt == 'auto' and conf.get('HAVE_OPENSSL') == 1 and conf.get('HAVE_GCRYPT') == 0))
-conf.set10('HAVE_OPENSSL_OR_GCRYPT',
-           conf.get('HAVE_OPENSSL') == 1 or conf.get('HAVE_GCRYPT') == 1)
-lib_openssl_or_gcrypt = conf.get('PREFER_OPENSSL') == 1 ? libopenssl : libgcrypt
-
 default_dnssec = get_option('default-dnssec')
 if skip_deps
         default_dnssec = 'no'