X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fgetgroups.c;h=0f951b73baa61fcdfa6c71dcd5b398d838898a13;hb=e1bb3dab9a2dca414eab231c33afd3fad19e7924;hp=717f90e4acc6049623302d84fc5c01b81efb4b13;hpb=4dc7e74d299f19bce7337f1c7dfda7d455a77c19;p=gnulib.git

diff --git a/lib/getgroups.c b/lib/getgroups.c
index 717f90e4a..0f951b73b 100644
--- a/lib/getgroups.c
+++ b/lib/getgroups.c
@@ -1,5 +1,5 @@
 /* provide consistent interface to getgroups for systems that don't allow N==0
-   Copyright (C) 1996 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1999, 2003 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
@@ -20,20 +20,22 @@
 #include <config.h>
 #include <stdio.h>
 #include <sys/types.h>
+#include <errno.h>
+#include <stdlib.h>
 
-char *xmalloc ();
+#include "xalloc.h"
 
-/* On Ultrix 4.3, getgroups (0, 0) always fails.
-   This function handles that special case and lets the system-
-   provided function handle all others.  */
+/* 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
+   process.  This function handles that special case and lets the system-
+   provided function handle all others. */
 
 int
-getgroups (n, group)
-     size_t n;
-     GETGROUPS_T *group;
+getgroups (int n, GETGROUPS_T *group)
 {
-  int ng;
+  int n_groups;
   GETGROUPS_T *gbuf;
+  int saved_errno;
 
 #undef getgroups
 
@@ -41,17 +43,22 @@ getgroups (n, group)
     return getgroups (n, group);
 
   n = 20;
-  gbuf = NULL;
   while (1)
     {
-      gbuf = (GETGROUPS_T *) xrealloc (gbuf, n * sizeof (GETGROUPS_T));
-      ng = getgroups (n, gbuf);
-      if (ng < n)
+      /* 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 ng;
+  return n_groups;
 }