From b40b7e7bf66b7cbca2ad20aa840092fa00a1724d Mon Sep 17 00:00:00 2001
From: Nick Couchman <vnick@apache.org>
Date: Sat, 23 Jan 2021 21:57:41 -0500
Subject: [PATCH] GUACAMOLE-1133: Add build check for headers when libvncserver
 includes gcrypt support.

---
 configure.ac | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/configure.ac b/configure.ac
index 18c641ce..09985bbd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -519,6 +519,27 @@ then
     AC_CHECK_LIB([vncclient], [rfbInitClient], [VNC_LIBS="$VNC_LIBS -lvncclient"], [have_libvncserver=no])
 fi
 
+#
+# Underlying libvncserver usage of gcrypt
+#
+
+if test "x${have_libvncserver}" = "xyes"
+then
+
+    # Whether libvncserver was built against libgcrypt
+    AC_CHECK_DECL([LIBVNCSERVER_WITH_CLIENT_GCRYPT],
+                         [AC_CHECK_HEADER(gcrypt.h,,
+                                          [AC_MSG_WARN([
+  --------------------------------------------
+   libvncserver appears to be built against
+   libgcrypt, but the libgcrypt headers
+   could not be found. VNC will be disabled.
+  --------------------------------------------])
+                                           have_libvncserver=no])],,
+                    [[#include <rfb/rfbconfig.h>]])
+
+fi
+
 AM_CONDITIONAL([ENABLE_VNC], [test "x${have_libvncserver}" = "xyes"])
 AC_SUBST(VNC_LIBS)