[ease] Fix a segfault when closing Ease.

[Stéphane Maniaci <maniacis src gnome org>]

commit fbd638d36fe90e2b6eca580d18d43951fb2fea3e
Author: Stéphane Maniaci <stephane maniaci gmail com>
Date:   Thu Jun 24 22:38:42 2010 +0200

    Fix a segfault when closing Ease.

 src/ease-temp.vala |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/ease-temp.vala b/src/ease-temp.vala
index 38e8666..d3ed0db 100644
--- a/src/ease-temp.vala
+++ b/src/ease-temp.vala
@@ -144,6 +144,10 @@ public static class Ease.Temp : Object
 	 */
 	public static void clean()
 	{
+		if (folders == null) {
+			return;
+		}
+
 		string dir;
 		while ((dir = folders.poll_head()) != null)
 		{