Merge branch 'master' into nikitakit_ducks

diff --git a/synfig-core/configure.ac b/synfig-core/configure.ac
index dd40d94..33a733d 100644 (file)
--- a/synfig-core/configure.ac
+++ b/synfig-core/configure.ac
@@ -622,8 +622,11 @@ AC_SUBST(CXXFLAGS)
 AC_SUBST(CPPFLAGS)
 AC_SUBST(LDFLAGS)
 
-# this line is required for libtool 1.5.26 but must not be present for libtool 2.2.4...
-# AC_CONFIG_SUBDIRS(libltdl)
+# AC_CONFIG_SUBDIRS(libltdl) is required for libtool 1.5.26 but must not be present for
+# libtool 2.2.4. Problem seems to be that AC_LIB_LTDL (above) now calls AC_CONFIG_SUBDIRS
+# itself, through LTDL_INIT, _LTDL_SETUP, _LTDL_MODE_DISPATCH. We need to check the
+# condition that libltdl has already been registered with AC_CONFIG_SUBDIRS:
+m4_ifdef([_AC_SEEN_TAG(libltdl)], [], [AC_CONFIG_SUBDIRS(libltdl)])
 
 CONFIG_LIBS="-lsynfig"
 CONFIG_CFLAGS="$CONFIG_CFLAGS"