New modules 'unistr/u8-strcpy', 'unistr/u16-strcpy', 'unistr/u32-strcpy'.

[gnulib.git] / lib / getgroups.c

diff --git a/lib/getgroups.c b/lib/getgroups.c
index 4e0d53a..615bd4f 100644 (file)
--- a/lib/getgroups.c
+++ b/lib/getgroups.c
@@ -1,5 +1,6 @@
 /* provide consistent interface to getgroups for systems that don't allow N==0
-   Copyright (C) 1996, 1999 Free Software Foundation, Inc.
+
+   Copyright (C) 1996, 1999, 2003, 2006 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,15 +14,18 @@
 
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
 /* written by Jim Meyering */
 
 #include <config.h>
+
 #include <stdio.h>
 #include <sys/types.h>
+#include <errno.h>
+#include <stdlib.h>
 
-char *xmalloc ();
+#include "xalloc.h"
 
 /* On at least Ultrix 4.3 and NextStep 3.2, getgroups (0, 0) always fails.
    On other systems, it returns the number of supplemental groups for the
@@ -29,10 +33,11 @@ char *xmalloc ();
    provided function handle all others. */
 
 int
-getgroups (size_t n, GETGROUPS_T *group)
+getgroups (int n, GETGROUPS_T *group)
 {
   int n_groups;
   GETGROUPS_T *gbuf;
+  int saved_errno;
 
 #undef getgroups
 
@@ -40,17 +45,22 @@ getgroups (size_t n, GETGROUPS_T *group)
     return getgroups (n, group);
 
   n = 20;
-  gbuf = NULL;
   while (1)
     {
-      gbuf = (GETGROUPS_T *) xrealloc (gbuf, n * sizeof (GETGROUPS_T));
+      /* No need to worry about address arithmetic overflow here,
+        since the ancient systems that we're running on have low
+        limits on the number of secondary groups.  */
+      gbuf = xmalloc (n * sizeof *gbuf);
       n_groups = getgroups (n, gbuf);
       if (n_groups < n)
        break;
+      free (gbuf);
       n += 10;
     }
 
+  saved_errno = errno;
   free (gbuf);
+  errno = saved_errno;
 
   return n_groups;
 }