merges r30820 from trunk into ruby_1_9_2.

--
	* process.c (proc_setgroups): add GC guard to prevent intermediate
	  variable from GC.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@31512 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 1 deletions

diff --git a/process.c b/process.c
index e8830504ff..c1804922e1 100644
--- a/process.c
+++ b/process.c
@@ -4464,9 +4464,11 @@ proc_setgroups(VALUE obj, VALUE ary)
 	    }
 	    else {
 		gr = getgrnam(RSTRING_PTR(tmp));
-		if (gr == NULL)
+		if (gr == NULL) {
+		    RB_GC_GUARD(tmp);
 		    rb_raise(rb_eArgError,
 			     "can't find group for %s", RSTRING_PTR(tmp));
+		}
 		groups[i] = gr->gr_gid;
 	    }
 	}