Further refinement following rebase

Author: eddelbuettel

inst/include/Rcpp/Function.h

@@ -70,17 +70,13 @@ namespace Rcpp{
         }
 
         Function_Impl(const std::string& name, const std::string& ns) {
-#if R_VERSION < R_Version(4,6,0)
-            Shield<SEXP> env(Rf_findVarInFrame(R_NamespaceRegistry, Rf_install(ns.c_str())));
-            if (env == R_UnboundValue)
-            Shield<SEXP> env(R_getRegisteredNamespace(ns.c_str()));
-            if (env == R_NilValue)
-                stop("there is no namespace called \"%s\"", ns);
-#else
+#if R_VERSION < R_Version(4,6,0) || R_SVN_REVISION < 89746
             Shield<SEXP> env(R_getVarEx(Rf_install(ns.c_str()), R_NamespaceRegistry, FALSE, R_NilValue));
+#else
+            Shield<SEXP> env(R_getRegisteredNamespace(ns.c_str()));
+#endif
             if (env == R_NilValue)
                 stop("there is no namespace called \"%s\"", ns);
-#endif
             get_function(name, env);
         }