[gtk-vnc] Do an explicit check for libgcrypt

[Daniel P. Berrange <dberrange src gnome org>]

commit e45f1e6b6c5de26dbe010e4b2542827bd03bbc91
Author: Daniel P. Berrange <berrange redhat com>
Date:   Fri Feb 6 11:38:28 2015 +0000

    Do an explicit check for libgcrypt
    
    We can no longer assume that any gnutls install will include
    libgcrypt, so we must do an explicit check for it at configure
    time.
    
    Signed-off-by: Daniel P. Berrange <berrange redhat com>

 configure.ac    |    8 ++++----
 src/Makefile.am |    2 ++
 2 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index ecb33cf..bd4bb4e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -33,6 +33,8 @@ GIO_REQUIRED=2.10.0
 AC_SUBST(GIO_REQUIRED)
 GDK_PIXBUF_REQUIRED=2.10.0
 AC_SUBST(GDK_PIXBUF_REQUIRED)
+GCRYPT_REQUIRED=1.4.0
+AC_SUBST(GCRYPT_REQUIRED)
 GNUTLS_REQUIRED=1.4.0
 AC_SUBST(GNUTLS_REQUIRED)
 
@@ -242,11 +244,9 @@ AC_SUBST(PULSEAUDIO_CFLAGS)
 AC_SUBST(PULSEAUDIO_LIBS)
 
 
+AM_PATH_LIBGCRYPT($GCRYPT_REQUIRED)
+
 PKG_CHECK_MODULES(GNUTLS, gnutls >= $GNUTLS_REQUIRED)
-dnl Not all versions of gnutls include -lgcrypt and -lgpg-error, and we need it
-dnl explicitly for building MS Logon extension which calls
-dnl gcry_XXX APIs
-GNUTLS_LIBS="$GNUTLS_LIBS -lgcrypt -lgpg-error"
 AC_SUBST(GNUTLS_CFLAGS)
 AC_SUBST(GNUTLS_LIBS)
 
diff --git a/src/Makefile.am b/src/Makefile.am
index f143c90..7b9b862 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -36,6 +36,7 @@ libgvnc_1_0_la_LIBADD = \
                        $(GIO_LIBS) \
                        $(GTHREAD_LIBS) \
                        $(GDK_PIXBUF_LIBS) \
+                       $(LIBGCRYPT_LIBS) \
                        $(GNUTLS_LIBS) \
                        $(SASL_LIBS)
 libgvnc_1_0_la_CFLAGS = \
@@ -43,6 +44,7 @@ libgvnc_1_0_la_CFLAGS = \
                        $(GIO_CFLAGS) \
                        $(GTHREAD_CFLAGS) \
                        $(GDK_PIXBUF_CFLAGS) \
+                       $(LIBGCRYPT_CFLAGS) \
                        $(GNUTLS_CFLAGS) \
                        $(SASL_CFLAGS) \
                        $(WARN_CFLAGS) \