bug#43982: strerror return value

bug#43982: strerror return value

[Philipp Klaus Krause]

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This is just a very minor issue.

emacs contains two calls to strerror where the result is assigned
to a char *. However, according to the strerror specification, the
string returned by strerror should never be changed, so it would be
better to use const char * instead.

See the attached patch for the trivial fix.

[-- Attachment #2: emacs-strerror-const.patch --]
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diff --git a/lib-src/movemail.c b/lib-src/movemail.c
index 8016a4e373..4f9abc998a 100644
--- a/lib-src/movemail.c
+++ b/lib-src/movemail.c
@@ -580,7 +580,7 @@ pfatal_with_name (char *name)
 static void
 pfatal_and_delete (char *name)
 {
-  char *s = strerror (errno);
+  const char *s = strerror (errno);
   unlink (name);
   fatal ("%s for %s", s, name);
 }
diff --git a/src/emacs.c b/src/emacs.c
index 6ed970b9fd..e9e9661c39 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -1273,7 +1273,7 @@ main (int argc, char **argv)
 	      || (fcntl (STDIN_FILENO, F_DUPFD_CLOEXEC, STDOUT_FILENO)
 		  != STDOUT_FILENO))
 	    {
-	      char *errstring = strerror (errno);
+	      const char *errstring = strerror (errno);
 	      fprintf (stderr, "%s: %s: %s\n", argv[0], term, errstring);
 	      exit (EXIT_FAILURE);
 	    }

bug#43982: strerror return value

[Lars Ingebrigtsen]

Philipp Klaus Krause <pkk@spth.de> writes:

> This is just a very minor issue.
>
> emacs contains two calls to strerror where the result is assigned
> to a char *. However, according to the strerror specification, the
> string returned by strerror should never be changed, so it would be
> better to use const char * instead.
>
> See the attached patch for the trivial fix.

[...]

> -  char *s = strerror (errno);
> +  const char *s = strerror (errno);

Makes sense; I've now applied this to Emacs 28.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no