try an alterntive impl of wrap( const char*)

Author: romainfrancois

inst/include/Rcpp/internal/wrap.h

@@ -920,13 +920,11 @@ inline SEXP module_wrap<SEXP>( const SEXP& obj ){
 	return obj ;	
 }
 
-
-// special case - FIXME : this is not template specializations of wrap<>
 inline SEXP wrap(const char* const v ){ 
-    if (v == NULL)
-	return R_NilValue;
-    else
-	return Rf_mkString(v) ;
+	if (v)
+		return Rf_mkString(v) ;
+	else 	
+		return R_NilValue;
 }
 
 /**

inst/unitTests/cpp/wrap.cpp

@@ -138,12 +138,14 @@ List multimap_string_generic(){
 
 // [[Rcpp::export]]
 SEXP null_const_char(){ 
-    const char *p = NULL; return wrap(p); 
+    const char *p = NULL; 
+    return wrap(p); 
 }
 
 // [[Rcpp::export]]
 SEXP nonnull_const_char(){ 
-    const char *p = "foo"; return wrap(p) ; 
+    const char *p = "foo"; 
+    return wrap(p) ; 
 }
 
 // [[Rcpp::export]]