strerror: work around FreeBSD bug

Breaking strerror away from strerror_r re-exposed the FreeBSD
strerror(0) bug.

* lib/strerror.c (strerror): Special case 0.
Reported by Bruno Haible.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/ChangeLog b/ChangeLog
index 363ee1f..35497d0 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2011-06-06  Eric Blake  <eblake@redhat.com>
 
+       strerror: work around FreeBSD bug
+       * lib/strerror.c (strerror): Special case 0.
+       Reported by Bruno Haible.
+
        strerror-override: avoid bloating errno module
        * modules/errno (Files, configure.ac): Move replacement strings...
        * modules/strerror-override: ...to new module.

diff --git a/lib/strerror.c b/lib/strerror.c
index 8c41179..4dc0b65 100644 (file)
--- a/lib/strerror.c
+++ b/lib/strerror.c
@@ -45,10 +45,22 @@ strerror (int n)
   if (msg)
     return (char *) msg;
 
+  /* FreeBSD rejects 0; see http://austingroupbugs.net/view.php?id=382.  */
+  if (n)
+    msg = strerror (n);
+  else
+    {
+      int saved_errno = errno;
+      errno = 0;
+      msg = strerror (n);
+      if (errno)
+        msg = "Success";
+      errno = saved_errno;
+    }
+
   /* Our strerror_r implementation might use the system's strerror
      buffer, so all other clients of strerror have to see the error
      copied into a buffer that we manage.  */
-  msg = strerror (n);
   if (!msg || !*msg)
     {
       static char const fmt[] = "Unknown error %d";