From 71d109d4a5f9f19a3f22f24a06b3b1824766ba1e Mon Sep 17 00:00:00 2001
From: Francesco Chemolli <5175948+kinkie@users.noreply.github.com>
Date: Thu, 27 Apr 2023 16:42:02 +0000
Subject: [PATCH] Fix default build with libgnutls but absent GnuTLS headers
 (#1332)

Ensure that when libgnutls is found but any of the required GnuTLS
headers cannot be used, GnuTLS support is not enabled by default and an
explicit request for GnuTLS support is fatally rejected during
./configure. Otherwise, the build fails later anyway, during "make".

The problem was exposed by a mingw-cross build.
---
 configure.ac | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 2699d85e6d..e25587a390 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1093,7 +1093,8 @@ AS_IF([test "x$with_gnutls" != "xno"],[
     ## by testing for a 3.4.0+ function which we use
     AC_CHECK_LIB(gnutls,gnutls_pcert_export_x509,[LIBGNUTLS_LIBS="-lgnutls"])
   ])
-  AC_CHECK_HEADERS(gnutls/gnutls.h gnutls/x509.h gnutls/abstract.h)
+  # if any of the required headers is not found, signal we can't support gnutls
+  AC_CHECK_HEADERS([gnutls/gnutls.h gnutls/x509.h gnutls/abstract.h], [], [LIBGNUTLS_LIBS=""])
 
   SQUID_STATE_ROLLBACK(squid_gnutls_state) #de-pollute LIBS
 
-- 
2.47.2