refinement for String tests

plus NEWS entry
rolled Version and Date

Author: eddelbuettel

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: Rcpp
 Title: Seamless R and C++ Integration
-Version: 0.12.1
-Date: 2015-09-10
+Version: 0.12.1.1
+Date: 2015-09-21
 Author: Dirk Eddelbuettel, Romain Francois, JJ Allaire, Kevin Ushey, 
  Qiang Kou, Douglas Bates and John Chambers
 Maintainer: Dirk Eddelbuettel <[email protected]>

inst/NEWS.Rd

@@ -2,6 +2,16 @@
 \title{News for Package 'Rcpp'}
 \newcommand{\cpkg}{\href{http://CRAN.R-project.org/package=#1}{\pkg{#1}}}
 
+\section{Changes in Rcpp version 0.12.2 (expected 2015-11-01 or later)}{
+  \itemize{
+    \item Changes in Rcpp API:
+    \itemize{
+      \item Before creating a single String object from a \code{SEXP}, ensure
+      that it is from a vector of length one (issue #375)
+    }
+  }
+}
+      
 \section{Changes in Rcpp version 0.12.1 (2015-09-10)}{
   \itemize{
     \item Changes in Rcpp API:

inst/include/Rcpp/String.h

@@ -72,18 +72,14 @@ namespace Rcpp {
 
         /** construct a string from a single CHARSXP SEXP */
         String(SEXP charsxp) : data(charsxp), valid(true), buffer_ready(false), enc(Rf_getCharCE(charsxp)) {
-            if (! ::Rf_isString(data))
-                throw ::Rcpp::not_compatible("expecting a string");
-            if (::Rf_length(data) != 1)
+            if (::Rf_isString(data) && ::Rf_length(data) != 1)
                 throw ::Rcpp::not_compatible("expecting a single value");
             Rcpp_PreserveObject(data);
             RCPP_STRING_DEBUG( "String(SEXP)" ) ;
         }
 
         String(SEXP charsxp, const std::string& enc) : data(charsxp), valid(true), buffer_ready(false) {
-            if (! ::Rf_isString(data))
-                throw ::Rcpp::not_compatible("expecting a string");
-            if (::Rf_length(data) != 1)
+            if (::Rf_isString(data) && ::Rf_length(data) != 1)
                 throw ::Rcpp::not_compatible("expecting a single value");
             Rcpp_PreserveObject( data );
             set_encoding(enc);