Feature/issue935 (#940)

* change to Shelter (closes #101)

* news and changelog updates

Author: eddelbuettel

ChangeLog

@@ -3,6 +3,15 @@
 	* R/Attributes.R: better handle pre-existing RcppExports.cpp,
 	RcppExports.R when calling compileAttributes()
 
+2019-02-09  Ralf Stubner  <[email protected]>
+
+	* Rcpp-modules.Rmd: Added example for .factory
+
+2019-01-31  Dirk Eddelbuettel  <[email protected]>
+
+	* inst/include/Rcpp/protection/Shelter.h (Rcpp): Only increase
+	nprotected count if object is not NULL (suggested by Stepan Sindelar)
+
 2018-12-26  Zhuoer Dong  <[email protected]>
 
 	* vignettes/Rcpp-quickref.Rmd: Fix three bugs: use `Named()`, define

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: Rcpp
 Title: Seamless R and C++ Integration
-Version: 1.0.0.1
+Version: 1.0.0.2
 Date: 2018-11-11
 Author: Dirk Eddelbuettel, Romain Francois, JJ Allaire, Kevin Ushey, Qiang Kou,
  Nathan Russell, Douglas Bates and John Chambers

inst/NEWS.Rd

@@ -17,12 +17,14 @@
       \item A new plugin was added for C++20 (Dirk in \ghpr{927})
       \item Fixed an issue where 'stale' symbols could become registered in
       RcppExports.cpp, leading to linker errors and other related issues.
-      (\ghit{733}; \ghit{934})
+      (Kevin fixing \ghit{733} and \ghit{934})
     }
     \item Changes in Rcpp Documentation:
     \itemize{
       \item Three small corrections were added in the 'Rcpp Quickref
       vignette (Zhuoer Dong in \ghpr{933} fixing \ghit{932}).
+      \item The \code{Rcpp-modules} vignette now has documentation for
+      \code{.factory} (Ralf Stubner in \ghpr{938} fixing \ghit{937}).
     }
   }
 }

inst/include/Rcpp/protection/Shelter.h

@@ -23,25 +23,25 @@ namespace Rcpp {
     template <class T>
     class Shelter {
     public:
-        Shelter() : nprotected(0){}
+        Shelter() : nprotected(0) {}
 
-        inline SEXP operator()(SEXP x){
-            nprotected++;
-            return Rcpp_protect(x) ;
+        inline SEXP operator()(SEXP x) {
+            if (x != R_NilValue) nprotected++;
+            return Rcpp_protect(x);
         }
 
         ~Shelter(){
-            Rcpp_unprotect(nprotected) ;
-            nprotected = 0 ;
+            Rcpp_unprotect(nprotected);
+            nprotected = 0;
         }
 
     private:
-        int nprotected ;
+        int nprotected;
 
         // not defined on purpose
         Shelter(const Shelter&) ;
         Shelter& operator=(const Shelter&) ;
-    } ;
+    };
 }
 
 #endif