net-p2p/dogecoin-qt: 1.14.9 boost_system patch

- Adding patch to fix boost_system configure error for 1.14.9 per PR #3928 from Dogecoin
  Core devs.

Signed-off-by: Victor Skovorodnikov <victor3.14@yandex.com>

net-p2p/dogecoin-qt/dogecoin-qt-1.14.9.ebuild

@@ -64,6 +64,7 @@ pkg_pretend() {
 }
 
 src_prepare() {
+	PATCHES=( "${FILESDIR}"/1.14.9-boost-system.patch )
 	if use pie && use ssp ; then
 		PATCHES+=( "${FILESDIR}"/hardened-all.patch )
 	elif use pie && ! use ssp ; then

net-p2p/dogecoin-qt/files/1.14.9-boost-system.patch

@@ -0,0 +1,40 @@
+diff --git a/configure.ac b/configure.ac
+index d8df3d1..a95b068 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -692,7 +692,34 @@ define(MINIMUM_REQUIRED_BOOST, 1.60.0)
+ 
+ dnl Check for boost libs
+ AX_BOOST_BASE([MINIMUM_REQUIRED_BOOST], AC_MSG_RESULT(ok), AC_MSG_ERROR(Need at least boost 1.60.0))
+-AX_BOOST_SYSTEM
++
++dnl As of boost 1.69.0, boost_system is header-only and
++dnl as of version 1.89.0 it is fully removed.
++dnl We conditionally check whether to include boost_system
++dnl based on the value specified in version.hpp
++
++AC_MSG_CHECKING([for boost >= 1.69.0])
++CHECK_BOOST_SYSTEM=yes
++TEMP_CPPFLAGS="$CPPFLAGS"
++CPPFLAGS="$BOOST_CPPFLAGS $CPPFLAGS"
++AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[
++    @%:@include <boost/version.hpp>
++  ]], [[
++    #if BOOST_VERSION >= 106900
++    // No boost_system needed
++    #else
++    #  error we need to include boost_system
++    #endif
++  ]])],
++  [ AC_MSG_RESULT(yes); CHECK_BOOST_SYSTEM=no ],
++  [ AC_MSG_RESULT(no); CHECK_BOOST_SYSTEM=yes ]
++)
++CPPFLAGS="$TEMP_CPPFLAGS"
++
++if test x$CHECK_BOOST_SYSTEM = xyes; then
++  AX_BOOST_SYSTEM
++fi
++
+ AX_BOOST_FILESYSTEM
+ AX_BOOST_PROGRAM_OPTIONS
+ AX_BOOST_THREAD