sort,numfmt: with --debug, diagnose failure to set locale

* src/sort.c (main): With --debug, warn upon setlocale() failure,
which can happen due to incorrectly specified environment variables,
or due to memory exhaustion (simulated with ulimit -v), etc.
* tests/misc/sort-debug-warn.sh: Add a test case.
See also http://savannah.gnu.org/bugs/11004

2 files changed, 11 insertions, 3 deletions

diff --git a/src/numfmt.c b/src/numfmt.c
index 24bf45b37..109947e20 100644
--- a/src/numfmt.c
+++ b/src/numfmt.c
@@ -1429,10 +1429,11 @@ int
 main (int argc, char **argv)
 {
   int valid_numbers = 1;
+  bool locale_ok;
 
   initialize_main (&argc, &argv);
   set_program_name (argv[0]);
-  setlocale (LC_ALL, "");
+  locale_ok = setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);
 
@@ -1558,6 +1559,9 @@ main (int argc, char **argv)
   if (format_str != NULL && grouping)
     error (EXIT_FAILURE, 0, _("--grouping cannot be combined with --format"));
 
+  if (debug && ! locale_ok)
+    error (0, 0, _("failed to set locale"));
+
   /* Warn about no-op.  */
   if (debug && scale_from == scale_none && scale_to == scale_none
       && !grouping && (padding_width == 0) && (format_str == NULL))
diff --git a/src/sort.c b/src/sort.c
index 7ce059282..9396f46dc 100644
--- a/src/sort.c
+++ b/src/sort.c
@@ -4187,10 +4187,11 @@ main (int argc, char **argv)
   char *files_from = NULL;
   struct Tokens tok;
   char const *outfile = NULL;
+  bool locale_ok;
 
   initialize_main (&argc, &argv);
   set_program_name (argv[0]);
-  setlocale (LC_ALL, "");
+  locale_ok = setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);
 
@@ -4664,7 +4665,10 @@ main (int argc, char **argv)
         error (0, 0, _("using %s sorting rules"),
                quote (setlocale (LC_COLLATE, NULL)));
       else
-        error (0, 0, _("using simple byte comparison"));
+        {
+          error (0, 0, "%s%s", locale_ok ? "" : _("failed to set locale; "),
+                 _("using simple byte comparison"));
+        }
       key_warnings (&gkey, gkey_only);
     }