setting attributes on primitives is an error now

git-svn-id: https://svn.r-project.org/R/trunk@88032 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: maechler

doc/NEWS.Rd

@@ -35,6 +35,15 @@
       \item .
     }
   }
+
+  \subsection{BUG FIXES}{
+    \itemize{
+      \item Setting \code{\link{attributes}} on primitive functions is an
+      error now; previously, it modified without copying, as noticed by
+      \I{Henrik Bengtsson} on the R-devel mailing list.
+    }
+  }
+
 }
 \section{\Rlogo CHANGES IN R 4.5.0}{
   %% \subsection{SIGNIFICANT USER-VISIBLE CHANGES}{
@@ -781,7 +790,7 @@
 
       \item \code{trace(coerce, ..)} now works correctly, fixing \PR{18823}
       thanks to \I{Mikael Jagan}.
-      
+
       \item \command{R CMD check} now also reports bad symbols in
       package shared objects linked in from local static libraries
       (\PR{18789}).

src/library/base/man/Primitive.Rd

@@ -1,6 +1,6 @@
 % File src/library/base/man/Primitive.Rd
 % Part of the R package, https://www.R-project.org
-% Copyright 1995-2018 R Core Team
+% Copyright 1995-2025 R Core Team
 % Distributed under GPL 2 or later
 
 \name{Primitive}
@@ -26,6 +26,8 @@
 
   All primitive functions are in the base namespace.
 
+  You cannot set \code{\link{attributes}} on primitive functions.
+
   This function is almost never used: \code{`name`} or, more carefully,
   \code{\link{get}(name, envir = baseenv())} work equally well and do
   not depend on knowing which functions are primitive (which does change

src/main/attrib.c

@@ -1071,15 +1071,14 @@ static SEXP as_char_simpl(SEXP val1)
 
     if (inherits(val1, "factor"))  /* mimic as.character.factor */
 	return asCharacterFactor(val1);
-
-    if (!isString(val1)) { /* mimic as.character.default */
+    if (isString(val1))
+	return val1;
+    // else  mimic as.character.default :
 	SEXP this2 = PROTECT(coerceVector(val1, STRSXP));
 	SET_ATTRIB(this2, R_NilValue);
 	SET_OBJECT(this2, 0);
 	UNPROTECT(1);
 	return this2;
-    }
-    return val1;
 }
 
 
@@ -1349,6 +1348,8 @@ attribute_hidden SEXP do_attributesgets(SEXP call, SEXP op, SEXP args, SEXP env)
     /* Do checks before duplication */
     if (!isNewList(attrs))
 	error(_("attributes must be a list or NULL"));
+    if (isPrimitive(object))
+	error(_("Cannot modify attributes on primitive functions"));
     int i, nattrs = length(attrs);
     if (nattrs > 0) {
 	names = getAttrib(attrs, R_NamesSymbol);

tests/reg-tests-1e.R

@@ -1908,7 +1908,16 @@ if(englishMsgs)
           "invalid type (list) for variable 'mpg'",
           "object 'count' not found",
           "invalid type (closure) for variable 'count'")))
-## the last one differed 
+## the last one differed
+
+
+## Setting attributes on primitive functions .. [Henrik Bengtsson, R-devel]
+stopifnot(is.primitive(sum))
+msum <- sum
+assertErrV(void <- structure(sum, foo = TRUE))
+assertErrV(attributes(msum) <- list(foo = NA))
+## both examples, the first a special case of the 2nd, did not error, but *modified* the base::sum primitive
+
 
 
 ## keep at end