gethostname errno

[Kevin Ryde]

        * posix.c (scm_gethostname): Preserve errno across free() call.

Though I don't suppose gethostname ever reports an error, not with the
way the buffer size is increased automatically.

This will be for the 1.6 branch too I think.

--- posix.c.~1.126.~    2004-02-29 09:22:52.000000000 +1000
+++ posix.c     2004-03-18 14:02:04.000000000 +1000
@@ -1748,7 +1748,7 @@
 {
   /* 256 is for Solaris, under Linux ENAMETOOLONG is returned if not
      large enough.  */
-  int len = 256, res;
+  int len = 256, res, save_errno;
   char *p = scm_malloc (len);
   SCM name;
 
@@ -1761,7 +1761,9 @@
     }
   if (res == -1)
     {
+      save_errno = errno;
       free (p);
+      errno = save_errno;
       SCM_SYSERROR;
     }
   name = scm_makfrom0str (p);