activate options(warn = <val>) checking (after > 6 years "not yet") via \env{R_WARN_BOUNDS_OPT}

git-svn-id: https://svn.r-project.org/R/trunk@89337 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: maechler

doc/NEWS.Rd

@@ -176,6 +176,10 @@
 
       \item Error messages from failed Rd \verb{\Sexpr} code now include
       the call from the original condition (if available).
+
+      \item When the environment variable \env{R_WARN_BOUNDS_OPT} is set to
+      \code{"yes"}, \code{options(warn = val)} will check if \code{val} is
+      inside \code{-1:2}; this may happen unconditionally in the future.
     }
   }
 
@@ -520,9 +524,6 @@
       \item On Windows terminals \kbd{Ctrl-C} now breaks out of waiting for
       keyboard input, fixing \PR{18982}.
 
-      \item \code{pretty(ch)} again correctly works with \code{ch} a
-      character vector of numbers.
-
       \item The default \code{summary()} and its factor method now
       label missing values \samp{NAs} rather than \samp{NA's},
       fixing a decades-old grammatical faux pas inherited from S
@@ -577,7 +578,10 @@
       thanks to \I{Leo Mada} and other \I{\dQuote{R-help}ers}.
 
       \item \code{vignette(\var{pkg}::\var{topic})} is now a documented
-      usage variant and confines vignette retrieval to the specified package. 
+      usage variant and confines vignette retrieval to the specified package.
+
+      \item \code{pretty(ch)} again correctly works with \code{ch} a
+      character vector of numbers.
     }
   }
 }

src/library/base/man/options.Rd

@@ -1,6 +1,6 @@
 % File src/library/base/man/options.Rd
 % Part of the R package, https://www.R-project.org
-% Copyright 1995-2025 R Core Team
+% Copyright 1995-2026 R Core Team
 % Distributed under GPL 2 or later
 
 \name{options}
@@ -456,16 +456,19 @@ getOption(x, default = NULL)
       \option{--verbose}.}
 
     \item{\code{warn}:}{integer value to set the handling of warning
-      messages by the default warning handler.  If
-      \code{warn} is negative all warnings are ignored.  If \code{warn}
+      messages by the default warning handler.  In the future, this value
+      is checked to be one of \code{-1, 0, 1, 2}.  For now, setting
+      environment variable \env{R_WARN_BOUNDS_OPT} to \code{"yes"}
+      activates that check.
+      If \code{warn} is negative all warnings are ignored.  If \code{warn}
       is zero (the default) warnings are stored until the top--level
       function returns.  If 10 or fewer warnings were signalled they
       will be printed otherwise a message saying how many were
       signalled.  An object called \code{last.warning} is
       created and can be printed through the function
       \code{\link{warnings}}.  If \code{warn} is one, warnings are
       printed as they occur.  If \code{warn} is two (or larger, coercible
-      to integer), all warnings are turned into errors. While sometimes
+      to integer), all warnings are turned into errors.  While sometimes
       useful for debugging, turning warnings into errors may trigger
       bugs and resource leaks that would not have been triggered otherwise.}
 

src/main/options.c

@@ -1,6 +1,6 @@
 /*
  *  R : A Computer Language for Statistical Data Analysis
- *  Copyright (C) 1998-2025   The R Core Team.
+ *  Copyright (C) 1998-2026   The R Core Team.
  *  Copyright (C) 1995, 1996  Robert Gentleman and Ross Ihaka
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -685,11 +685,11 @@ attribute_hidden SEXP do_options(SEXP call, SEXP op, SEXP args, SEXP rho)
 		}
 		if (k == NA_INTEGER)
 		    error(_("invalid value for '%s'"), CHAR(namei));
-#ifdef _NOT_YET_
+#ifndef _ALLOW_WARN_OUT_OF_BOUNDS_OPT_
 		char *p = getenv("R_WARN_BOUNDS_OPT");
 		if ((p && (strcmp(p, "yes") == 0)) && (k < -1 || k > 2)) {
 		    int k_n = (k < 0) ? -1 : 2;
-		    REprintf(_("value for '%s' outside of -1:2 is set to %d\n"),
+		    warning(_("value for '%s' outside of -1:2 is set to %d\n"),
 			     CHAR(namei), k_n);
 		    k = k_n;
 		}
@@ -894,7 +894,7 @@ attribute_hidden SEXP do_options(SEXP call, SEXP op, SEXP args, SEXP rho)
 		if (TYPEOF(argi) != LGLSXP || LENGTH(argi) != 1)
 		    error(_("invalid value for '%s'"), CHAR(namei));
 		Rboolean k = asRbool(argi, call);
-#ifdef NO_QUIET_AND_VERBOSE 
+#ifdef NO_QUIET_AND_VERBOSE
 		if(k && R_Verbose)
 		    error(_("cannot set both options 'quiet' and 'verbose' to TRUE"));
 #endif
@@ -905,7 +905,7 @@ attribute_hidden SEXP do_options(SEXP call, SEXP op, SEXP args, SEXP rho)
 		if (TYPEOF(argi) != LGLSXP || LENGTH(argi) != 1)
 		    error(_("invalid value for '%s'"), CHAR(namei));
 		Rboolean k = asRbool(argi, call);
-#ifdef NO_QUIET_AND_VERBOSE 
+#ifdef NO_QUIET_AND_VERBOSE
 		if(k && R_Quiet)
 		    error(_("cannot set both options 'quiet' and 'verbose' to TRUE"));
 #endif