Allow the tests to be explicitly disabled to avoid floating dependnecy
issues. This is not really an issue with RSS but is on previous releases.

RP 2017/6/27
Upstream-Status: Pending

Index: gtk-doc-1.25/configure.ac
===================================================================
--- gtk-doc-1.25.orig/configure.ac
+++ gtk-doc-1.25/configure.ac
@@ -161,6 +161,11 @@ if test "x$GCC" = "xyes"; then
 	fi
 fi
 
+AC_ARG_ENABLE([tests],
+	AS_HELP_STRING([--enable-tests],
+	[enable tests (default=yes)]),,
+	[enable_tests="yes"])
+
 dnl if glib is available we can enable the tests
 PKG_CHECK_MODULES(TEST_DEPS, [glib-2.0 >= 2.6.0 gobject-2.0 >= 2.6.0],
 	[	glib_prefix="`$PKG_CONFIG --variable=prefix glib-2.0`"
@@ -171,6 +176,11 @@ PKG_CHECK_MODULES(TEST_DEPS, [glib-2.0 >
 		build_tests="no"
 	]
 )
+if test "x$enable_tests" != "xyes"; then
+	gtk_doc_use_libtool="no"
+	build_tests="no"
+fi
+
 AM_CONDITIONAL(GTK_DOC_USE_LIBTOOL, test -n "$LIBTOOL" -a x$gtk_doc_use_libtool = xyes )
 dnl this enable the rule in test/Makefile.am
 AM_CONDITIONAL(BUILD_TESTS, test x$build_tests = xyes)