[OLPC-devel] [PATCH] Fail gracefully if getgroups() fails

[Jordan Crouse]

uClibc is pretty stuck on using legacy 16 bit UIDs.  So when one turns off
CONFIG_UID16 in the Linux kernel, some syscalls have the annoying tendency to
return an error when they aren't normally expected to, including getgroups().  

The following patch makes coreutils/test.c act fail gracefully if getgroups() 
returns a -1.  This fixes a problem on the One Laptop Per Child ROM image
whereby we were getting odd Memory exhausted messages for '[' and 'test'.

Found by Mitch Bradley <wmb at firmworks.com>
-------------- next part --------------
[PATCH]: coreutils/test.c - fail gracefully if getgroups() fails.

Avoid a memory error if getgroups() returns a -1.

---
Index: busybox-1.1.3/coreutils/test.c
===================================================================
--- busybox-1.1.3.orig/coreutils/test.c	2006-08-22 08:28:57.000000000 -0600
+++ busybox-1.1.3/coreutils/test.c	2006-08-22 08:40:01.000000000 -0600
@@ -540,8 +540,11 @@
 static void initialize_group_array(void)
 {
 	ngroups = getgroups(0, NULL);
-	group_array = xrealloc(group_array, ngroups * sizeof(gid_t));
-	getgroups(ngroups, group_array);
+
+	if (ngroups > 0) {
+		group_array = xrealloc(group_array, ngroups * sizeof(gid_t));
+		getgroups(ngroups, group_array);
+	}
 }
 
 /* Return non-zero if GID is one that we have in our groups list. */